quote:
Then CPT violates known physical laws.
No no no no no. I think I am not very well conveying CPT and where it diverges from the issue of the radioisotopic decay rate. The theoretical realm of CPT does not directly as a requirement include accelerated radioisotopic decay--it is not needed for CPT to unfold. They are linked indirectly by a statement of practical deduction--if CPT occured, radioisotopic decay most probably happened as well. CPT only 'violates physical laws' in the context of this statement--that has auxilliary hypotheses that might not even be correct--and thus its disconfirming significance is not as great as you imply.
quote:
You must have some pretty stunning evidence to propose violations of known physical laws. Where is this evidence?
Firstly, there are no "violation(s) of known physical law(s)", there is only the issue of the radioisotopic decay rate. The only possible situation of evidence that I can think of is that of CPT itself--if CPT occured it would be evidence in favor of an accelerated decay rate because of what it implies for the geological record. Therefore, potential falsifiability of accelerated decay lies within the confirmation of CPT.
quote:
Without evidence, why should you be taken any more seriously than them?
Because CPT explains a lot of geological data.
quote:
Let me sum up your lengthy explanation: using Glatzmaier's simulations as a point of departure, you speculate that under CPT conditions rapid magnetic reversals could happen. But a) you're only speculating
This is about as significant as me saying "Evolution is only a theory".. This degree of speculation is about the same as mainstream geologys 'speculation' on the significance of basal tension as a tectonic driving force. Glatzmaier's analysis shows that the behavior of the geodynamo can vary greatly depending on variables like CMB heat flow, core geometry, relative viscosity, etc.--variables which would be far more variable during a phase of runaway subduction. It is reasonable therefore, to hypothesize that extreme behavior in the geodynamo would occur during CPT.
quote:
b) CPT conditions could never happen
The onus is on you to support this assertion. Please note that your statement here requires that you (a) know what conditions CPT implies and (b) that you can demonstrate that they could never occur. Support it or withdraw it.
quote:
c) you have no evidence CPT conditions have ever occurred. Start with evidence, Chris. Find evidence that says, "This demands that the continents moved rapidly." Stop trying to shoehorn the evidence into the Biblical myth.
You don't seem to fully understand how science is done--or more accurately the many ways science is and can be done.. Indeed I do not either, however I do believe that an inductive methodology (of course, my scientific methods are hardly confined to inductive logic) of scientific explanation should not be referred to as 'shoehorn[ing] the evidence into the biblical myth'. I have accurately stated several times that you are
not looking for evidence for CPT, you are looking for evidence (data) that can be explained by CPT and NOT by modern geology. I have also argued that the modern uniformitarian view of geology has a remarkable ability to continue molding itself, modifying auxilliary hypotheses after another without the ultimate theory suffering variations in the degree of confirmation/credibility--how could you not with all that time? Modern geology is specified to the point where it rather fails the virtue of refutability in the philosophy of science. This virtue of theories is a matter of degree measured by the cost of retaining the hypothesis in the face of imaginable events. The degree is measured by how clearly we cherish the previous beliefs that would have to be sacrificed to save the hypothesis. The greater the sacrifice, the more refutable the hypothesis. Modern geology gives very little sacrifice--so much so that it would require something like finding a human skull in cambrian rock record to even begin to be questioned. In fact, I can't think of too many other imaginable events except like anomalies in the fossil record that would be considered candidates for disconfirming evidence. So much more of modern geology's survivability is in the virtue of conservism and generality than in refutability. Furthermore in the context of our discussion, those imaginable events should be formulated while also considering the predictions of CPT. The reason the human skull example is considerable is because this 'anomaly' is an imaginable event that would not also disconfirm CPT. However other imaginable events, such as a lithosphere that does not thicken with age, the current forces of tectonics, etc. are not reasonable imaginable events because CPT expects what PT predicts at least approximately what CPT would predict as well so its potential disconfirmation is rendered null in light of the competing theory.
quote:
I think you're greatly overestimating the contribution of slab pull, but more on that later. The density of the oceanic crust is around 2.9 gm/cm3, that of the asthenosphere (the upper mantle) around 3.25 gm/cm3. The density of the oceanic crust is less than the upper mantle, just as I said.
That isn't all you said, and what you initially said was wrong as I pointed out.
quote:
But you're correct about the overall density. The oceanic crust is carried upon the lithosphere. When new lithosphere and oceanic crust is created at mid-oceanic ridges, the net density is not as great as the mantle. But as the ocean floor ages and cools it aggregates more and more material at it's base (maybe at the Moho interface, but I couldn't find anything that was specific) and gradually becomes more dense. The older the sea floor, the thicker and more dense it is, and the deeper that part of the ocean is as the sea floor subsides.
You're correct that at subduction zones the sea floor and underlying lithosphere is more dense than the asthenosphere into which it descends, but it isn't dramatic. I can't find a single website with all the figures, but poking about here and there seems to indicate that subducting sea floor has a density of 3.28 gm/cm3, which is only 1% more dense than the aesthensphere. This isn't a difference capable generating the rapid descent of plates into the mantle that you require.
While there has been recent focus on slab pull, and while some geologists think its contribution might be significant, this is doubtful. Several thousand miles of sea floor is only going to be stretched and strained in detectable ways if slab pull were the primary factor. A significant role for the push from the ridge is also doubtful, as the sea floor would pile up in a manner similar to how a rug bunches up if pushed from an edge. While no one within geology yet claims a definitive answer, it is likely that ridge push, mantle currents and slab pull all make contributions.
Ok, I will say 'no' on several fronts. The total body force of slab pull can be shown to be significant. Slab pull is comprised of downward gravitational body forces acting on the cold lithosphere due to thermal contraction and an elevation in the olivine-spinel phase change boundary. The olivine-spinel phase change occurs at a certain depth in the surrounding mantle. However because the isotherm is adjusted in the lithosphere at that depth, the phase change occurs at a shallower depth and lower pressure in the lithosphere. Thermal contraction, however, is the dominating contributor to this total body force. The basic significance of the force of thermal contraction can be seen just by putting the coefficient of thermal expansion to work. Using an equation (sorry no greek) to find change in density;
dp = -pa
vdT, where p is density, a
v is the coefficient of thermal expansion, and
dT is change in temperature. From a hypothetical density of 3000 kg/m
3, a
v = 3x10
-5, and a temperature difference of 1200 K;
dp = 108 kg/m
3, more than a 3% increase in density. Using more accurate complex equations, Turcotte and Schubert in
Geodynamics estimate a total slab pull body force of 4.9 x 10^13 N m^-1 on the descending lithosphere.
Here you've stated that "this isn't a difference capable of generating the rapid descent of plates into the mantle that you require", if you still hold to the accuracy of your assertion, it is up to you to support it.
The general consensus among geophysicists and geologists alike is that slap pull probably is the most significant force acting on the oceanic lithosphere. It has been numerically shown to create stresses in the lithosphere an order of magnitude greater than "ridge push" (gravitational sliding) (see
Geodynamics). I have not seen any numbers regarding the forces associated with basal traction, however it is probably negligible in the oceanic lithosphere as has been suggested by results from nonlinear rheological plate models of global tectonics separated by faults with low friction to test hypotheses on plate driving mechanisms against plate velocities and stresses (Bird, 1998; also see Richardson, et al., 1979). Also, if you compile data on total trench length and compare it against plate velocity, you will notice that all the fast and superfast spreading occurs in oceanic plates connected to subducting slabs, seemingly indicating that the slab pull force is indeed significant and that at least gravitational sliding is negligible. The reason significant large scale plate deformation is not seen is because these forces are not
that significant. Gravitational sliding is not significant enough to cause the plate to flex to any observational significance, let alone buckle and fold, and slab pull is not significant enough to overcome the elastic strength of the lithosphere to manifest itself on the surface in the form of faulting and, volcanism, etc. The whole of the oceanic lithosphere moves in response to these body forces as a coherent plate and these tensional stresses thus propogate its full length over the deformable mantle. It is likely that slap pull, gravitational sliding, and basal tractions probably all contribute, however slab pull most plausibly has the greater contribution.
Bird, P., Testing Hypotheses on plate-driving mechanisms with global lithosphere models including topography, thermal structure, and faults.
J. Geophys. Res. 103, 1998. 10115-29
Richardson, R. M., Solomon, S. C., and Sleep, N. H. Tectonic stress in the plates.
Rev. Geophys. Space Phys. 17, 1979. 981-1019
quote:
What you're doing is called opinion shopping. There's always a broad range of opinion and expression in any field of science.
Firstly, that is not what I am doing, with the exception of a few instances of me mistakenly saying "uniformitarian geology" instead of adding the correct modifiers I have accurately described the position of the general consensus in geology. Secondly, if I was 'opinion shopping' then that some geologists consider the principles of modern geology 'catastrophic uniformitarianism' or 'new uniformitarianism' or 'modern uniformitarianism', etc. is completely inconsistent with your original arguments here. You've stated that it is an oxymoron, NOT an opinion. You've claimed that "there is no other kind of 'uniformitarianism' than the classical" principle. Therefore these variations with other geologists are not 'opinions' they are just wrong according to you. This is not the case, however. Geologists do refer to current geological principles as 'uniformitarian' (with an appropriate descriptive modifier like 'new', 'modern', "actualist", or 'catastrophic') because not
all of the statements of classical uniformitarianism have been discarded.
quote:
As I've said, a science that accepts a wide variety of rates at which processes can proceed is not compatible with the term "uniformitarian", and that's why the term isn't used to characterize the field of geology anymore.
No, I think you are still confused about the word 'uniformitarianism'. See above. Also, to further explain, Hutton published the proposal that Earth's history could be explained in terms of processes observed in the present; that is, "the present is key to the past." This was the beginning of uniformitarianism. Lyell, in his
Principles of Geology, modified Hutton's ideas and applied this philosophy to explain geological features in terms of relatively gradual everyday processes. Modern actualist uniformitarianism holds that the geologic record is the product of both slow, gradual processes and naturally occuring catastrophes. The scale of events may change, but modern uniformitarianism still holds that the physical laws operating today are key to the past. Therefore the modern understanding doesn't completely exclude the word 'uniformitarianism', but may be referred to as 'modern', 'new', etc. Uniformitarianism as a guiding principle.
quote:
It's no mystery why you'd like to use the term. You'd like to characterize modern geology as rejecting rapid change for philosophical rather than sound reasons. You'd like to use the term "uniformitarian" because it conveys the notion that geology rejects rapid motion of continents and formation of geological layers not for sound evidential reasons, but simply because it rejects any rapid change. But this isn't true, because geology understands that many processes can happen rapidly.
No, this would just be stupid. I have never once argued this and I think it is foolish of you to think that I would argue something like this.
quote:
So clearly you understand that referring to geology as just "uniformitarian geology" isn't accurate.
Ultimately you are right, it is a bit misleading to say exclusively 'uniformitarian geology'.
quote:
Please stop. Because use of the term "uniformitarian" is primarily a tool of mispresentation, in keeping with the Forum Guidelines concerning mispresentations I will suspend you for 24 hours every time you use it.
Well this is your forum, you do have the power to quibble about whatever you want--But go right ahead, I could use a good laugh.
quote:
As I've explained many, many times, EvC Forum exists to explore Creationism's claim to be legitimate science. To that end, participants are expected to make their case for their perspective in a forthright and scientific manner. It is not up to others to make their case for them.
Participants are expected to make their case for their perspective??
Clearly, you don't even know my perspective!!! I will argue in favor of what I actually hold to be true and accurate. I will not argue in favor of some strawman of my perspective that you created just because it is an easy target.
quote:
You offered a figure of 1028 joules, and you've been asked to support it.
CPT is not 'my case'. I provided the 10^28 J figure and explained how it was determined as requested: from gravitational potential energy. What more is there needed to know?? Gravitational potential energy is NOT COMPLICATED and obviously does not rely on a set of auxilliary hypotheses that could have some variability within CPT. Baumgardner's numerical and computer models spit it out. How in the world is that not sufficient explanation of how the 10^28 J figure was determined?? Furthermore, the confined box within which mantle convection simulations were run used a realistic mantle depth so I see no reason to believe there could be significant error in the number..
quote:
You've claimed heat would not be a problem, and you've been asked to explain how this could be the case.
I have explained this... Just THINK about it.. Gravitational potential energy...How is gravitational potential energy released?? In the case of a descending oceanic lithosphere moving toward the bottom of the mantle..where is that heat going to be released? This is not complicated.
quote:
In science, new proposals to overturn old theory require evidence and supporting argument. This is what you're being asked to provide. If this doesn't make sense to you then you shouldn't participate here.
I am NOT yet trying to propose CPT as a new paradigm of geology. How can you not know where I stand after all my participation on this forum?? Theories have varying degrees of credibility. I am not here to argue that the credibility of CPT exceeds that of mainstream PT and that is not my argument. If that perspective is not compatible with the purpose of this forum, well then not only is the purpose of this forum stupid and pointless (except to beat up on creationists tahat think they have a good model of earth history) but I guess that means I have nothing to contribute. Evidently the analysis of hypotheses and any new or underdeveloped theories cannot take place on this forum.
quote:
And that's what you're here to do, persuade us. Telling us to go research it ourselves, or telling us to just accept a figure because Baumgardner's computer spit it out, is not persuasion but evasion.
Regarding Baumgardner's 10^28 figure, I've explained countless times where the figure came from, it is not complicated and if you have a problem with it, explain what that problem is. Telling me that you won't accept it because the computer spit it out isn't a sufficient counter argument. That is like me saying "well my geology text says the outer core is a fluid, but that isn't good enough for me!" What is your problem with the figure and the way it was determined (as I have explained how it was determined several times). Do you have reason to question Baumgardner's numerical and computer models or not? Calculating Gravitational potential energy is NOT difficult..
quote:
This approach will just bring you more suspensions.
You can suspend me all you want, but this is just silly.
Hi Edge,
quote:
IMHO, it [slab pull] doesn't exist. There are several lines of evidence. One is the pre-trench bulge that TC referred to earlier. There is no reason for this to happen if tensional forces cause the motion.
I think you may misunderstand what is thought to cause the peripheral bulge. The bulge/upwarp is a manifestation of the oceanic lithosphere--under horizontal strain--as it will flex due to the applied vertical end load of the adjacent plate it delves under. The vertical force and bending moment (angle of subduction) are a result of the gravitational body forces acting on the descending plate. The bulging response at trenches is analogous to what is observed around seamounts and ocean islands like Hawaii. The adjacent lithosphere does not simply flex downard near the vertical load but produces a radial bulge in response to the loading.
quote:
I believe that once the slab begins to descend, indeed, it is in tension, however, the problem is that the thing breaks up too easily to transmit tensile forces out beyond the trench. This is shown by fault-plane solutions for deep earthquakes at convergent boundaries.
Interesting, but I am not aware of any such research that concludes this. Therefore I don't think there is any data to indicate that the tensional stresses in the subducting slab will not be propogated through the rest of the rigid lithosphere it is connected to. Laboratory deformation experiments on some metastable minerals have been shown to display a shear instability called transformational faulting. However, this instability involves sudden failure by localized superplacity in thin shear zones where the metastable host mineral transforms to a denser, finer grained phase. Thus, as I understand it, the metastability model of transformational faulting is not the same as an occurance of brittle fracture and will not cause deep slabs to disconnect from the parent unsubducted oceanic lithosphere. Disconnection of oceanic lithosphere does appear to occur, but it is at significant depth and thus the slap pull force is still significant. I also understand that modeling metastability suggests that the slab pull force of a deflected phase change boundaries may be hindered by allowing a wedge of low density metastable olivine to survive at depths below the phase change boundary. Nevertheless, the presence (let alone magnitude) of this metastable olivine has not been determined through tomographic and other seismological methods. But even if it is there it is not likely to cancel out the total slab pull bodyforce and will probably remain numerically more significant than gravitational sliding several times over.
quote:
For sure. There should be all kinds of pull-apart structures and mid-plate volcanics that could not be explained any other way.
What makes you think the tensional stresses would be high enough to manifest itself on the surface in such a way?
quote:
I don't think TC has actually thought much about these things, though he seems to be fairly well-read. There is no critical analysis in his thinking
What am I not analyzing critically enough? I have thought about these things...
quote:
particularly when it comes to Baumgardner, and some of the basics are way out of kilter
What basics?
quote:
I hope that he never reads anything on the plume controversy, that would take us months to overcome.
You appear to be trying to make me look ignorant.. I think that I have a better understanding of geodynamics than you seem to believe. I don't care if you don't give me credit where it is due (hell, that rarely ever happens) but for you to do the inverse I am not going to just sit back and tolerate.
Hi again Percy,
quote:
Chris, please, spare us the bullshit. You've been pushing CPT for almost four years now. You *do* espouse it, you are *not* "merely considering it", and those on the other side are certainly *not* considering it. You've put an enormous amount of intellectual time and energy into it. This is not a casual dalliance or flirtation for you, but rather represents quite a considerable investment
The only bullshit here is your understanding of my position..or your inability to somehow comprehend it, or your willful ignorance of it. The quantity of intellectual time and energy I have invested in CPT is not logically connected to my acceptence of it (or degree of acceptence of it) or of anything. It is NOT the business of scientists as scientists to accept the hypotheses they research, whatever its degree of confirmation.
quote:
If you were truly "merely considering it" then you would have rejected it at the outset for violations of known physical laws and for just being mind-poppingly unbelievable. Those interested in exploring ideas from the frontiers of science do not wed themselves to Biblical myths at the expense of basic scientific principles and thinking.
You might want to work on getting a better understanding of the PHILOSOPHY of Scientific acceptence, explanation, and justification. You have just described the flawed outcome of the epistomologically flawed schema of (t) and (s), where schema (t) is stated as "
H then
TI;
TI, therefore
H is confirmed" and likewise schema (s) is "
H then
TI; not
TI, therefore
H is disconfirmed" where
H= hypothesis and
TI=test implication. The problem is that the first premise (that of
H then
TI) will always contain auxiliary hypotheses. The actual form of the first premeses is (n) if
H and
A1 and
A2 and ...
An then
TI.
A1,
A2, etc. are auxiliary hypotheses--hypotheses assumed when it is claimed that
H implies
TI. Therefore, to be more realistic about the first premise of (t), the formal conclusion can only be: Therefore,
H is false, or
A1 is false, or
A2 is false, or ...
An is false. The problem is that you think determination of
A1,
A2, and
An, etc. is so simple within confirmatory evidence of CPT relative to PT. In order to best determine those auxilliary hypotheses (required to be true for falsification of
H, the hypothesis), models of the hypothesis must be developed sufficiently. This is the problem with producing the diagnostic evidences you desire--the details of CPT have not been sorted out well yet and so it is very difficult to say that certain auxilliary hypotheses are correct when determining confirmation and disconfirmation of CPT. How well do you understand those 'basic scientific principles and thinking" that you seem to think you are advocating??
quote:
Chris, you've been pushing CPT for a long time. It's time to quit the nonsense and present some evidence.
This is like me refering to geology as "uniformitarian", so if you were me, and I were you, I guess you would be suspended. I have made it clear several times that you are NOT looking for EVIDENCE you are looking for a specific type of evidence. CPT has plenty of evidence just as does PT. These evidences act as epistemic reasons to confirm CPT. Similarily, Newtonian mechanics and general relativity share evidence. If PT was ever to be replaced by CPT, the paradigm shift would be similar to that seen when Einstein's Physics replaced Newtonian mechanics. The evidence of past centuries for Newtonian mechanics carried over, within limits, as evidence for Einstein's physics; for, as far as it goes, it fits both!
"What is thus illustrated by Einstein's relativity is more modestly exemplified elsewhere, and generally aspired to: the retention, in some sense, of old theories in new ones. If the new theory can be so fashioned as to diverge from the old only in ways that are undetectable in most ordinary circumstances, then it inherits the evidence of the old theory rather than having it overcome it." W. V. Quine and J. S. Ullian, "Hypothesis." From
The Web of Belief, 2nd ed., 1978 pp. 76-77.
quote:
We are not exploring CPT with you because it is self-evidently in the "extremely unlikely" category. We don't think it's science, and we don't think there's any evidence supporting it.
Then you don't know what science is, and you don't know what evidence is. Until you can stop misrepresenting CPT as if it had no evidence I am not about to show you possible situations of inquiry where CPT may be able to explain the data better than PT because I just don't want to hear this demonstratable nonsense.
quote:
You can't even agree with the other CPT advocate here, Tranquility Base, who unlike your single year believes 500 years were required to move the continents and create the geological layers. You can't both be right, and given that there's not a shred of evidence for either time frame, you're likely both wrong. Very wrong. And it is the lack of evidence that enables you both to equally passionately push for conflicting scenarios whose time frames disagree by a factor of 500.
You have a problem with tentativity and variation among theories trying to explain the same data? This is not unhealthy because they are different hypothetical frameworks of inquiry. If either of us claimed that our model was demonstraitably superior but could not support its supperiority, that would be unhealthy. I don't know about TB, but I have not done this.
quote:
Chris, those on the other side of this discussion do not reject CPT because they are atheists or because they're not sufficiently Christian or because they're Islamic. They reject it because the evidence tells a completely different story. The CPT reinterpretation of the evidence is a fairy tale world that doesn't exist.
Is that not what we are here to discuss?
quote:
Since radioactive decay was accelerated, find some uranium deposits that despite being below critical mass went critical and began producing fission.
This does not belong in this thread.
quote:
Find a line of demarcation on the sea floor that marks the boundary between rapid deposition during the flood year and the more traditional contemporary rate of deposition.
If you had a good understanding of the distribution and thickness of sediments on the ocean floor you probably would understand that this probably could not be determined.
quote:
If CPT happened, the evidence should be obvious and everywhere.
How do you know? The only way to come to this conclusion is to formulate test implications for CPT and with CORRECT auxilliary hypotheses, deduce confirmation of CPT. You've shown nothing which indicates that this statement is true.
quote:
I'm posting this in admin mode because I'm not trying to start a discussion. I'm trying to encourage you to be scientific in the science forums.
My logic and scientific methodology is not inconsistent with what is known about the philosophy of science--in justification, acceptance, explanation, etc.
This message has been edited by TrueCreation, 07-17-2005 02:13 AM
"...research [is] a strenuous and devoted attempt to force nature into the conceptual boxes supplied by professional education. Simultaneously, we shall wonder whether research could proceed without such boxes, whatever the element of arbitrariness in their historic origins and, occasionally, in their subsequent development." Kuhn, T. S.;
The Structure of Scientific Revolutions, pp. 5, 1996.
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