Cosmic periodicity

The validity of the general periodic function extends into the periodicity of the chemical elements under extreme conditions, showing up a cosmic periodic law that includes all elements and anti-elements. The obvious link of this function with the curvature of space-time provided a mechanism for the production of nuclides in an equilibrium process, within a black hole, that matches the observed abundances. 

However, reaction 7 suffers other shortcomings, eg, entropy problems. Other proposals range from trace peroxidic contaminants to ionic mechanisms for generating peroxides (1) to cosmic rays (17). In any event, the initiating reactions are significant only during the induction period (18). 

Much more important is the problem of the survival of microorganisms for longer periods of time under the extreme conditions present in outer space there is absolutely no comparison between these conditions and those in laboratories on Earth The first question is in what form such microorganisms would be subjected to cosmic conditions ... 

There is no doubt that the most important parameter in the organisms familiar to us is water content. The lapidary sentence no life without water is valid for all aspects of biogenesis, whether on the primeval Earth or on another heavenly body. The life processes in all living species known to Man are based on liquid water, which has a number of special properties (Brack, 1993). The dehydrating effect of a high vacuum is assumed to be the most important limiting factor in the transport of microbes between heavenly bodies. This effect would naturally depend on the time required for such a transfer, since some spores can survive for what are, in cosmic dimensions, short periods. 

The generation process for radiocarbon in the atmosphere makes C02 which enters the biosphere because of the long lifetime the mixing is essentially perfect. We assumed the rate of production to be constant which turns out to be somewhat incorrect. Variations of about 10 percent can be seen back in time to early Egyptian periods and before. The earth s magnetic field was apparently weaker then as the cosmic rays delivered to the surface and the atmosphere were more intense. 

The method assumes that the average cosmic ray flux has been constant over the mean-life of 81Kr (t81 + 3.07 x 105y) and over the overall exposure time of the sample cosmic rays. Furthermore, it is assumed that the exposure geometry has remained fixed over the period of irradiation, but no other assumptions are made regarding shielding. 

The global average production rate of any nuclide, Q(t), at any time, t, will be primarily dependent on the cosmic ray intensity, I(t). If the intensity varies sinusoidally with a period T(u) = 2n/T), Q(t) will also vary sinusoidally. The standing crop of a nuclide in the sea water column for a production function, Q(t) = Q (1 + a cos tot), a being the amplitude, can be deduced to be 0... 

The amplitude attenuation factor, 1 + (tu/Ai)2 for nuclides satisfying relation [14], for various values of Ax and T are presented in figure 9. It is obvious from figure 9 that the attenuation is minimal when Ai > u>, i.e., when the removal residence time of the nuclide from sea water is less than the period in the variation of cosmic ray intensity. 

Figure 9. Calculated attenuation factors for various values of T (period in the sinusoidal cosmic ray intensity variations) and A (the total rate constant). See section on deep-sea sediments and historical records for discussion.

In the preceding discussion, we have calculated the attenuation factors for 10Be for three periods, 200, 7 x 103 and 10s years. Of these the 200 and 7000 year periods are well established and have been ascribed to solar cycle variations and earth s magnetic field excursions, respectively. For detailed calculations on the effect of these variations on the production rates of isotopes by cosmic rays reference is made to Castagnoli and Lal, 75.)... 

From the point of view of GCE, one is interested primarily in effects averaged over long periods of time of the order of Gyr but in dwarf galaxies which may have experienced only a few star formation bursts over a Hubble time the sporadic character may have appreciable effects, especially when one bears in mind that much of the abundance data for such objects comes from H II regions which are intrinsically the result of a current burst, and there is indeed evidence for a cosmic dispersion in certain element abundance ratios such as N/O in such objects (see Chapter 11). 

The motions of the Sun and Moon form the basis of our calendars. The measurement of mechanical time is largely based on the periodic reoccurrence of certain phenomena the rhythm of day and night, the seasons, or the cyclic reappearance of the planets and stars in the sky. The flow of change is attested by the apparently irreversible global evolution of the Cosmos. Cosmic time, eternity s yardstick, is the measure of universal change, of the evolution of matter, and this evolution is essentially one of nuclear complexiflcation, driven by stellar forces. 

A cosmochemical periodic table, illustrating the behavior of elements in chondritic meteorites. Cosmic abundances are indicated by symbol sizes. Volatilities of elements reflect the temperatures at which 50°/o of each element would condense into a solid phase from a gas of solar composition. As in Figure 1.2, the chemical affinities of each element, lithophile for silicates and oxides, siderophile for metals, and chalcophile for sulfides, are indicated. Some of the most highly volatile phases may have remained uncondensed in the nebula. Stable, radioactive, and radiogenic isotopes used in cosmochemistry are indicated by bold outlines, as in Figure 1.2. Abundances and 50% condensation temperatures are from tabulations by Lodders and Fegley (1998). 

The fraction of incoming cosmic rays that generate nuclear reactions is quite low. In a meteorite traveling in space, about one in 108 of the target atoms undergoes a nuclear reaction in a 10-Myr period. However, the cosmogenic nuclides that they produce can be measured to estimate the time that an object has been exposed to cosmic rays. Table 9.1 shows some of the nuclides that are used to estimate cosmic-ray exposure ages in meteorites and in materials from planetary surfaces. 

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