The earth is probably more than 10,000 years old.

1. Radiometric dating Con cites the University of North Carolina as claiming that K-Ar dating is unreliable, and making other extraordinary claims. It's not UNC, the claims are made in web pages posted under the disclaimer: “This material does not necessarily represent any organization, including the University of North Carolina and the State of North Carolina. . ., Unless otherwise indicated, all articles are written by David Plaisted. ” [17. . http://tinyurl.com...] Dr. Kevin R. Henke, a Ph. D. in geology [18. . http://tinyurl.com...], writes, “Dr. David Plaisted is a computer scientist and creationist critic of orthodox geology … Dr. Plaisted seems to be a very nice and sincere guy. However, his essays on creationism contain numerous errors; unproven speculations and accusations; . .. citations from anonymous emails, newspaper articles and other questionable sources; misinterpretations of the literature and serious misunderstandings of geology, chemistry, physics, biology, and other topics that are clearly beyond his area of expertise. [19. . http://tinyurl.com...] Plaisted is a computer scientist, and his papers are neither peer-reviewed nor do they cite peer-reviewed literature. They are bogus. The original article finding the erroneous age in diamond dating speculates on two possible causes for the error. The Nature article eliminates the isochron error as the problem, leaving the material cause as a possibility. The date was for material in an inclusion in the diamond, not the diamond itself. The actual cause of the error is not known. That means that there is an unresolved case which scientists are actively trying to explain. Con illogically supposes that if even one case of error is unexplained, the whole method is invalidated. So if we do not know why a wall clock stopped, then they have lost all credibility and are we then justified in invalidating everything ever done with a clock. No, again Con has no statistics to prove the generality. An example of the consistent accuracy of radiometric dating is in the data on the age of the earth. The most direct means for calculating the Earth's age is a Pb/Pb isochron age, derived from samples of the Earth and meteorites. The age is 4.55 billion years. In addition, hundreds of radiometric measurements of the age of the earth have been made using Ar-Ar, Sm-Nd, Rb-Sr, Lu-Hf, and Re-Os. [20. Dalrymple, G. Brent, 1991. The Age of the Earth, California, Stanford University Press. 474 pp. ISBN 0-8047-1569-6] The data is summarized at [21. . http://tinyurl.com...] The consistency is remarkable, all dates are near 4.5 billion years. Cons argues that there are no large errors in length measurement with rulers, implying that there should be no cases of large errors in radiometry. Carpenters have a rough check on length just by sight. They know a measurement more than, say, twice is wrong. There is no comparable sense of the age of a mineral specimen. That's why there is no much attention to cross-checking. I gave a list of the alternative methods of cross-checking dates. The point is that there are many means used to ensure accuracy. There are a half dozen or so ways to verify that radioactive decay rates have been nearly constant over the ages. [22. Sisterna, P. , and H. Vucetich, 1990. "Time variation of fundamental constants: Bounds from geophysical and astronomical data" in Physical Review D (Particles and Fields) 41, no. 4, pp. 1034-1046. ] They all show no significant variation. 2. Sandstone and the Grand Canyon Con did not provide scientific references to any means that sand could be formed in less than tens of millions of years, nor any reference to literature on how stone could be quickly formed from the sand, or how it could be eroded so quickly. It is all empty speculation of believers who want it to be possible. Con points to a vertical wall of wet sand a few feet high. The sand is held together by the surface tension of the water (something first explained by Einstein, presumably on his day off). Surface tension cannot support a thousand foot wall, and as soon as the sand dries even the short wall will collapse. 3. Varves The paper con cited concerning stratification in layers specifies sand of diameters 0.07 mm and 0.11 mm between plates 5 mm apart. “In contrast, we obtain only segregation but not stratification for two experiments using spherical beads of size 0.55 mm and 0.77 mm (so that the larger grains have smaller repose angle). ” [23. . http://arxiv.org...] There being no closely spaced plates nor carefully sorted grain sizes in varves, this unusual sorting due to selective angle of repose does not apply, It would not in any case explain seasonal pollen grains changing with climate in the varve layers. 4. Dendrochronology It's not true that tree ring data showing an 11,919 year old history used radiocarbon dating. The source says it was done using tree rings alone. The method of using multiple trees in the same area, overlapping in time ensures that the accuracy is either one year. That's more accurate than carbon dating. I merely noted that the methods agree, but if the carbon dating is ignored, the dendrochronology is proof on it's own. Con never showed that multiple rings were anything other than rare, or that scientists could not cope with their occurrence. Multiples were merely flagged as something needing attention to get one year accuracy. Polystrate fossils According to scientists, polystrate fossils are fossils which were buried in a geologically short time span either by one large depositional event or by several smaller ones. Tree roots are found in the layer below the trunk showing the tree was growing in the ground. The upper part of the tree is then partially engulfed in flood sediment. It's not true that the tree spans layers claimed to cover millions of years. [24. . http://en.wikipedia.org...] Polystrate fossils were explained over a hundred years ago, by geologists who believed in creationism. [25. . http://tinyurl.com...] By comparison, here is a partial description of the layers of the Grand Canyon: Kaibab Limestone: 300 feet thick, formed in a marine environment. Fossils include molluscs, . .. Toroweap formation: 200 feet thick, varying from predominantly sandstone to limestone. Coconino Sandstone, 50-300 feet thick. Sandstone formed from desert sand dunes. Numerous reptile tracks preserved in the sandstone. Hermit Shale: 300 feet thick. Siltstones formed from deposits in swamps and lagoons. Supai group: 600-700 feet thick; plant fossils I. .. . Redwall Limestone: 400-650 feet thick. Abundant fossil evidence of . .. a warm, shallow clear ocean. [26. . http://www.chem.tufts.edu...] How did a great flood quickly put reptile tracks on a sandstone layer below material from swamps and lagoons, in turn below plant fossils, and all below ocean fossils? Con cites creationist literature saying fossils are not strictly time-ordered. The articles give no scientific references. It appears they are ciing species discovered to have overlapping historical periods. Summary of the Debate A fundamental error repeated in Con's arguments is that if a method ever shows errors then it "loses credibility. " To prove unreliability, there must be statistics showing that errors occur in a high percentage of cases, and Con presented no such statistics. Scientists achieve confidence in geological dating by endless cross-checking with different dating methods and by checking multiple samples. The age of the earth is established using hundreds of measurements with different isotope pairs. There is no science behind flood geology of the Grand Canyon. Varves and tree rings are independent of radiometry and give precise measurement of times more than 10,000 years ago. Con relied heavily on non-peer-reviewed religious pages. The authors were discredited. The Bible itself is not a scientific source.