Nuclear cosmochronology

doi:10.1016/0003-4916(60)90025-7

Annals of Physics

Volume 10, Issue 2, June 1960, Pages 280-302

https://doi.org/10.1016/0003-4916(60)90025-7 Get rights and content

Abstract

In the studies described in this paper we make quantitative use of the radio-active decays of uranium and thorium in cosmochronology in much the same manner as these decays have been employed in geochronology. The paper is divided into two quite different parts representing different views as to the immediate source of the material that now constitutes the solar system.

Model 1. The Autonomous Galaxy. From its origin, the Galaxy has been an autonomous system—no further important additions of material from intergalactic space have taken place at subsequent times. Star formation, stellar evolution, and nucleosynthesis have declined at a steady exponential rate over the whole lifetime of the Galaxy. The duration of nucleosynthesis is found to be independent of this rate over rather wide limits.

Model 2. Steady-State Cosmology and Galactic-Intergalactic Exchange of Matter. The abundance of the elements in intergalactic matter has reached a steady state through interchange with galaxies in which stars produce elements beyond hydrogen. As a consequence of this same point of view, the Galaxy acquired significant quantities of intergalactic material at various times. This occurred particularly about one billion years before the sun and solar system were formed. Except at epochs of addition of new gas, stellar activity has declined exponentially, as in Model 1.

Consideration of the decay of the radioactive isotopes Th²³², U²³⁵, U²³⁸, according to Model 1, leads to the conclusion that the age of the Galaxy is 15₋₃⁺⁵ × 10⁹ years. Similar considerations according to Model 2 lead to the conclusion that the expansion time scale of the universe (the reciprocal of the Hubble constant H) is 11 ± 6 × 10⁹ years. The error can be reduced to ±2 × 10⁹ years if the present thorium-uranium ratio is chosen to give a $Pb^{208} Pb^{206}$ age for the solar system concordant with that given by $Pb>^{207} Pb^{206}$ , namely 4.5 × 10⁹ years. Applications to the chronology of the Galaxy can no longer be made in a simple manner but the age found in the Model 1 calculations would seem to be a lower limit.

References (17)

C.C. Patterson
Geochim. et Cosmochim. Acta
(1956)
B.M. Foreman et al.
J. Inorg. Nucl. Chem.
(1958)
A.H.W. Aten
Physics
(1957)
J.B. Oke
Astrophys. J.
(1959)
O.C. Wilson
Astrophys. J.
(1959)
E.M. Burbidge et al.
Revs. Modern Phys.
(1957)
E.E. Salpeter
Astrophys. J.
(1959)
M. Schmidt
Astrophys. J.
(1959)

There are more references available in the full text version of this article.

Cited by (76)

Using predictive Bayesian Monte Carlo- Markov Chain methods to provide a probablistic solution for the Drake equation
2019, Acta Astronautica
Citation Excerpt :
Other disagree with that point given the black hole in the center of the galaxy that is consuming starts at an unknown rate [30,61,62]. Kreifeldt [30] suggests that the rate of star generation is decreasing with time, having peaked in the past, which comports with the suggestions of Schmidt [61], and as an exponentially decreasing rate by Fowler and Hoyle [62]. While star formation is not observable, but the number of stars can be estimated to be between 100 and 400 billion.
Are we alone in the universe? It is an age-old question that continues to encourage interest and controversy among the public as well as academics. Development of explanations for life elsewhere ranges widely, but few mathematical models have been developed to measure the likelihood of concurrent, intelligent life, and those that exist are widely speculative due to the lack of information. However, with the addition of information from Kepler explorations for new solar systems within our galaxy, and calculation of the potential number of stars in the expanse of the universe, data for a useful probabilistic model to determine the likelihood of life beyond Earth may be possible with the use of predictive Bayesian statistics. Predictive Bayesian statistical methods are designed to use limited, uncertain data, to develop results. The result provides a probability curve of the likelihood of life in the universe that includes both uncertainty and potential variability within the result to provide a means to define the probability of life in the galaxy as well as life within proximity to earth. That said, the results indicate that the probability we are alone (<1) in the galaxy is significant, while the maximum number of contemporary civilizations might be as few as a thousand. With so few concurrent civilizations, and such large distances, it is little surprise that the SETI project has not found that alien signal. Our nearest neighbor is 4 light years away, and there are under 100 stars within 50 light years, the total of the project's existence.
Toward an accurate determination of half-life of <sup>147</sup>Sm isotope
2018, Applied Radiation and Isotopes
Citation Excerpt :
In fact, the signatures of long-lived primordial isotopes, formed in the build-up of the solar system matter and still present in planetary materials, are expected to provide important constraints on the current paradigm of the solar system formation. To this aim, in their pioneering research work, Fowler and Hoyle proposed 238U-232Th and 235U-238U systems (Fowler and Hoyle, 1960). After that, methodologies based on the radioactivity of 87Rb, 147Sm, 187Re, 232Th, 238U, and 235U isotopes have been applied (Symbalisty and Schramm, 1981; Takahashi, 1998; Hiess et al., 2012).
The task of an accurate determination of alpha-decay rate of ¹⁴⁷Sm isotope, a topic of importance in both basic and applied science, has been performed in the present research following two different routes. First, a critical review and data analysis of the whole set of half-life values obtained till date yielded an average of 106.3 ± 0.5 Ga. Second, a one-parameter, semi-empirical model for alpha emission from nuclei, developed in the framework of quantum mechanical tunneling mechanism through a Coulomb-plus-centrifugal-plus-overlapping potential barrier, that yielded a value of 108.2 ± 3.0 Ga. The good agreement found between the half-life values obtained from these procedures represents a net progress toward the assessment of a reliable ¹⁴⁷Sm alpha-decay rate to be used in geo- and cosmo-chronological investigations.
Impact of systematic nuclear uncertainties on composition and decay heat of dynamical and disc ejecta in compact binary mergers
2023, Monthly Notices of the Royal Astronomical Society
Skyrme–Hartree–Fock–Bogoliubov mass models on a 3D mesh: IIb. Fission properties of BSkG2
2023, European Physical Journal A
Skyrme-Hartree-Fock-Bogoliubov mass models on a 3D mesh: IIb. Fission properties of BSkG2
2023, arXiv
High-precision Nuclear Chronometer for the Cosmos
2022, Astrophysical Journal

View all citing articles on Scopus

^☆: Supported in part by the joint program of the Office of Naval Research and the U. S. Atomic Energy Commission.

View full text

Nuclear cosmochronology☆

Abstract

Geochim. et Cosmochim. Acta

J. Inorg. Nucl. Chem.

Physics

Astrophys. J.

Astrophys. J.

Revs. Modern Phys.

Astrophys. J.

Astrophys. J.