³³⁸ Radiometric dating includes work with carbon-14 (from a few hundred years to 50,000 years ago), potassium-argon (for dates ranging from 100,000 years to 4.5 x 10 ⁹ years ago), rubidium-strontium (from 5 x 10 ⁷ to about 4.5 x 10 ⁹ years ago), lead isotopes (from 10 ⁸ to 4.5 x 10 ⁹ years ago) as well as fission- tracks (a few million to a few hundred million years ago) and thermoluminescence dating (used to date clay pottery). ³³⁹ Table 1:

Parent Isotope	Daughter Isotope	Half-life
Carbon-14		Nitrogen-14		5730
Potassium-40		Argon-40		xxxxx
Rubidium-87		Strontium-87		4.88 x 10 10
Samarium-147		Neodymium-143		1.06 x 10"
Lutetium-176		Hafnium-176		3.5 x 10 10
Thorium-232		Lead-208		1.4 x 10'°
Uranium-235		Lead-207		7.04 x 10 8
Uranium-238		Lead-206		4.47 x 10 9

³⁴⁰ Scientists estimate the universe unfolded from its state of infinite destiny ³⁴¹ —a moment commonly referred to as "the big bang"—approximately 1.3-2 x 10 ^io years ago. ³⁴¹ Typo: "destiny" should read "density."

^[1] The age of the earth lies somewhere between 4.43-4.57 x 10 ⁹ years (roughly around the time our solar system formed). With a few exceptions, most meteors are younger. Micrometeorites, however, with high levels of deuterium, suggest evidence of interstellar material predating our solar system. See F. Tera, "Congruency of comformable galenas: Age of the Earth" 12 th Lunar and Planetary Science Conference, 1981, p. 1088-1090; and I.D.R. Mackinnon and F.J.M. Rietmeijer, "Mineralogy of chondritic interplanetary dust particles" Rev. Geophys. 1987, 25:1527-1553. See also those particle age-related studies carried out by Klaus Bebblestein and Gunter Polinger, published in Physics Today, v.48, September 1995, p. 24-30, as well as by the Oxford University Press, 1994, under the title Particle Exam which includes in Chapter Sixteen fascinating data generated at the Deutsch Electron Synchrotron (DESY; pronounced "Daisy") in Hamburg and even input from the HERMES collaboration which at the time was using the HERA electron-proton collider to study nucleon spin. Bebblestein and Polinger have also written extensively on the recent though highly speculative claim that accurate algorithms must now exist which are in keeping with Wave Origin Reflection Data Series as currently set forth by the VEM™ Corporation.

^[1] (BGC) Berkeley Geochronology Center. Paul Renne. See Science August 12, 1994. p. 864.

^[1] 0ne must not forget the crater created by a meteor in the Arizona desert 50,000 years ago: Canyon Diablo with a diameter of 1207 meters and a depth of 174 meters.

^[1] Internal isochron measurements of Rb-Sr ages have shown the Norton County meteorite in the Aubrite group to have an age of 4.70 ^± 0.13 Ga(l Ga= 10 ⁹ years). The Krahenberg meteorite in the LL5 group has an estimated age of 4.70 ±0.01 Ga. As O'Geery indicates to Navidson, several of the XXXX samples also appear to have ages predating the formation of the earth. (Though the accuracy of those claims remains hotly contested). See D. W. Sears, The Nature and Origin of Meteorites (New York: Oxford University Press, 1978), p. 129; and Bailey Reims, Formation vs. Metamorphic Age (Cambridge, Massachusetts: The MIT Press, 1996), p. 182-235.

^[1] Robert T. Dodd, Meteorites: A Petrologic-Chemical Synthesis (Cambridge: Cambridge University Press, 1981). Dodd also explains on page 161: "A chondrite's first isotopic equilibration is usually called its formation. The time period between nucleosynthesis and formation is called the formation interval and that between formation and the present formation age. The time difference between a later isotopic disturbance and the present is called a metamorphic age. We have known for a quarter century that all chondrites are approximately 4.55 billion years old (Patterson, 1956) and for a decade that their history up to and including metamorphism encompassed no more than 100 million years (Papanastassiou and Wasserburg, 1969). What parts of this brief high-temperature history were occupied by chondrule formation, accretion, and metamorphism has been and remains unclear, for it is not always easy to tell which stage a particular isotopic system records."

347 Meteoritics: Asteroids, Comets, Craters, Interplanetary Dust, Interstellar Medium Lunar Samples, Meteors, Meteorites, Natural Satellites, Planets, Tektites Origin and History of the Solar System, Derek W. G. Sears, editor. Donald E. Brownlee, Michael J. Gaffey, Joseph I. Goldstein, Richard A. F. Grieve, Rhian Jones, Klaus Keil, Hiroko Nagahara, Frank Podosek, Ludolf Schultz, Denis Shaw, S. Ross Taylor, Paul H. Warren, Paul Weissman, George W. Wetherill, Rainer Wieler, associate editors. Published by The Meteoritical Society, v. 30, n. 3, May 1995. p. 244.

^[1] A possible solution to the date line scheme detailed by Navidson and O'Geery. It certainly lends weight to those theories favoring the historical significance of the samples, though it does nothing to resolve the presence of extraterrestrial and possibly even interstellar matter.