Could bio-design and rapid geo-column be introduced in science courses?

I think the largest matter which would need attention when it comes to teaching historical sciences is the format by which it is taught. I'm sure that College level students get the whole shabang but this simply isn't what is presented to high-school and more elementary students in science classes. The students have a considerably high lack in knowledge of how conclusions in science are made, why facts are labeled as facts, why theories are labeled as theories, and the information compiled in coming to the conclusion. For example, in talks of the Evolution of life and paleontology/fossils, radiometric dating is given as the answer to the question of 'how do you know that all these fossils are so old'. The students rarely will then be given the process by which samples are dated, and even more rare is explanations on how samples acquire dates. The geochemical processes in the crust and mantle, the well known anomalies of excess isotopes in various whole rock/mineral isochrons. And there most certainly is no mention of meaningless errorchrons, inheritance, Isotopic mixing, Open and closed system behaviors, weathering, metamorphism, mobility, and other areas of discordance and limitations. Without even given hints of the geochemical processes by which isochronic ratio's are produced, they haven't much room for intelligible question or argument. Basically, we need to either stop giving the students straw-men, or quit misleading them all together. The teaching of the ToE and its merit is highly sensitive and the format by which it is taught, the information that is given, and how it is given should be taken into careful consideration. It is tiring to hear youthful people see the the theory of the Evolution of life as an alternative to God.------------------

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[This message has been edited by TrueCreation, 06-30-2002]

"Nonsense. Even in HS, they are taught what assumptions are made an why. The sources of error are usually discussed along with applicability of the method. Otherwise, why teach the course! This isn't addition and subtraction we are talking about here."
--What HS classes did you take? Because I'm not talking about Geology 101 or anything like that, but general science. Not to mention that my copy of a HS earth science book does not go over assumptions made and why in any clarified manner.

quote:

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"The greater the percentage of lead present in the sample, the older the rock is. Scientists know that from a million grams of U-238, 1/7, 600 g of Pb-206 per year will be produced by decay. The U-Pb ratio can be used only when all the lead in the rock is known to have come from the decay of uranium. Because U-238 has an extremely long half-life of 4.5 billion years, it is most useful for dating geologic samples more than 10 million years old."

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--Exactly[/i] the point. I have known this for some time and am irritated when I hear YEC's argue this as RvX and the like did some time ago. This is the point because they don't know this and get the impression because of popular belief which is not addressed in the public schools that Evolution is an alternative to God. Many do make this association who are informed of this.------------------

"I don't know the greater context, but you're textbook quote is a simplified view of the U/Pb process. Hopefully, it was presented as such."
--Yes it was very simplified. While simplification is fine, to go without mentioning or hinting at discordant findings and other things along that line is a bit misleading as a student learns these things. What is also given in the book is that the decay of radioisotopes has been shown to be unaffected by environmental conditions. While this is in the majority, true, in the students mind this is a stumbling block because they now may have the impression that a statement such as 'the greater the percentage of lead present in the sample, the older the rock is' and then going on to say 'The U-Pb ratio can be used only when all the lead in the rock is known to have come from the decay of uranium' gives them the impression that the latter is irrelevant but was mentioned anyways."Now, as I understand it, the U/Pb process is a pretty strong method. It is usually done on zircons, which are quite solid containers of the elements involved."
--Zicons themselves in SHRIMP analytical technique, for instance, radiogenic Pb is shown to vary within most tested zircon grains on a 20um spatial scale[such as in: Compston; 1997]. Some spots are found to show excess Pb of up to 30 times expected values so I wouldn't agree that they are very uniformly trustable as a dating method for zircon isochrons. Heterogeneity is vastly out of order. There is also an approximately sinusoidal, variation in ²⁰⁶Pb/²³⁸U apparent ages with orientations in baddeleyite crystals which are not detected in zircon or monazite crystals. Though radiogenic ²⁰⁸Pb/²⁰⁶ and ²³²Th/²³⁸U both vary with orientation. Usually attributed to real compositional variation reflecting zones of anisotropic primary crystal growth. Different effects in mineral grains and zones within them renders U-Th-Pb dating in high question and is pretty much up to the investigators' interpretations. Interpretations which are usually based on expectations determined by the geological contexts of the rocks being dated.
--There are also problems with Zircon Inheritance and chemical weathering.--What do you think of the patterns in mineral U-Th-Pb Ages for Pitchblende, uranitite, monazite, zenotime, monazite, zircon and tanite, samarskite, thorite, titanite, euxenite, etc.?"Regardless, detailed study of radiometric dating methods sure seems to be beyond the scope of a high school class. Where I encountered in was in an upper-level college geology course."
--I can agree with you here, however for the geochemical processes to go unmentioned isn't all too good. These types of class discussions with the teacher should be encouraged.------------------

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[This message has been edited by TrueCreation, 07-01-2002]

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[This message has been edited by TrueCreation, 07-01-2002]

But of course! Something like that Percy . Preferably this would be more accurate:Snelling, Rollinson, Dasch, Goldich and Gast, Baumgardner, Austin, Depaolo and Wasserburg--My sources weren't online, but were from books. Radioisotopes and the age of the earth with linking information from other articles (dasch, Goldich et al., Depaolo et. al.)--Oh, the rarity of me borrowing the thoughts of other YEC scientists!------------------