Torch, Summer 1993

result of mixing, not aging. The remaining 28% could be the result of either mixing or aging. Thus it is clear that, in many cases, erroneous ages have been calculated from isochrons that are actually the result of mixing, not aging. The mixing model demonstrates that the ratios of elements and isotopes in igneous rocks are usually the result of incomplete mixing of different rocks while in a molten state, not the result of aging. Thus the radiometric method cannot be used to date rocks or determine the age of the earth. Claims that the earth is four and a half billion years old, based upon radiometric dating, are clearly unwarranted. In fact, the earth could be very young, as the Bible seems to indicate. Since science cannot determine absolute truth, we must look to other sources to determine truth concerning origins and to filter the conclusions that are obtained from scientific investigations. Since the Creator has given us His eyewitness testimony of creation in the form of the Bible, we would be wise to begin our investigation of origins with a thorough understanding of His Word. Article taken from Creation Research Society Quarterly, "A Demonstration of the Mixing Model to Account for Rb-Sr lsochrons" by Dr. Larry Helmick and Dr. Donald Baumann. Larry Helmick, a 1963 graduate of CedarviTle College, serves as professor of chemistry at Cedarville and teaches the Origins course. He holds a Ph.D. from Ohio University and has worked as a Faculty Research Fellow at NASA-Lewis Research Center. He has been at Cedarville since 1968. Donald Baumann Is a professor of biology and chemistry at Cedarville College and teaches tfle Radiation Biology course. He earned a Ph.D. from Iowa State University and has been at Cedarville since 1964. w In our Origins course at Cedarville College, we perform a demonstration of the isochron method of radiometric dating. We use a bag with various colored beads to represent the mixture of elements within a rock. By pulling beads from the bag, students can take a "rock sample" and calculate the age of the rock. The following description shows the possible outcomes of the demonstration and reveals the inconsistency of radiometric dating. Three individual rocks (A,B,C) with different concentrations of elements and isotopes are partially mixed by melting to form one larger rock (X). Eleven samples (A-K) are taken from various locations in rock X for analysis. Since rock Xis not homogeneous, the eleven samples will contain various ratios of the original three rocks, as shown in Table 1. The isotopic composition of each of the 11 samples is also given in Table 1. Four or five data points are arbitrarily selected and plotted, as shown in Graphs 1-4. These four graphs reveal four different results from radiometric dating of the same rock using the isochron method. The four graphs clearly show that there is a problem with radiometric dating using the isochron method. Graph 1: The ratios of the different isotopes yield an isochron (a straight line), which appears to verify the validity of the data, and an age has been calculated from the slope of the line. TABLE 1: ISOTOPIC COMPOSITION OF 11 SAMPLES OF ROCK X Rock Formed by Number of Atoms a1sr Sample Mixing a1sr 86Sr B7Rb a&Sr A 7 10 0 0.70 B 8 10 20 0.80 c 12 12 30 1.00 D 1A+1B+OC 15 20 20 0.75 E 2A+1B+OC 22 30 20 0.73 F 4A+1B+OC 36 50 20 0.72 G 1A+OB+1C 19 22 30 0.86 H 2A+OB+1C 26 32 30 0.81 I 6A+OB+1C 54 72 30 0.75 J 1A+18+1C 27 32 50 0.84 K 1A+4B+1C 51 62 110 0.82 Graph 2: Plotting a different combination of data from the same rock provides another isochron, but with a different slope and thus a different age. Can the same rock have two different ages? Graph 3: The data points are scattered. Therefore, the data appears to be invalid and no line can be drawn. Graph 4: The data produces a line with a negative slope, and therefore a negative age! Can a rock have a negative age? 87Rb Is it possible that the 4.5 billion- e&sr year age for the earth is simply the result of faulty analysis of 0.00 isotopic data and that the earth is 2.00 really not that old? Read the 2.50 1.00 accompanying article for another 0.67 analysis and explanation of the 0.40 isotopic data which has been 1.36 largely ignored by "old earth" 0.94 0.42 scientists because it does not fit 1.56 their preconceived ideas 1.77 concerning the age of the earth. Torch 11