Science in Christian Perspective

Letter to the Editor


[radiometric dating]

From: JASA 5 (December 1953): 3.

An interesting and possibly significant article appeared in the September 15, 1953 issue of the Physical Review (91, 1474, 1953), by David B. Rosenblatt. It is pointed out that Uranium isotope 236 has a half life which is geologically short, namely 2.4 x 107 years, decaying by alpha emission to Th232, whose half life is 1.4 x 1010 years. Therefore, if any U236 existed (in an, unexcited state, since U236 also fissions with sufficient excitation) at the creation of the elements, it would be unobserved today. He demonstrates that if U236 were created in an equal amount with U238, a reasonable assumption on the basis of nuclear stability, then the relative abundances of natural Th232 should be enriched by a factor of 4 over its neighboring nucleotdes on the abundance curve. The measured ratio of Thorium to Uranium abundance is 3.8.

While admitting that his considerations are speculative, he suggests some of the effects of such a "primeval endowment of U236." For example, the thermal condition of the earth would have been vastly different in its early geological history, since the U236 decay process would provide a large amount of energy. This energy would be sufficient to maintain the earth entirely molten for about 0.5 x 109 years, longer than thought under Urey's theory of accretion, radioactive heat melting, and subsequent cooling.

The principal interest for the Christian in this work is the effect the primeval U236 would have on age estimates from Uranium/Lead abundances, and from Helium content of rocks. A little consideration will show that Helium from U236 decay would be found, and would have been misinterpreted as a decay product from other radioactive series, thus giving an older than actual measured age of rocks by Helium methods. However, since Helium content determinations are considered unreliable for times earlier than about 500,000,000 years ago, "in general, an . . . analysis is used which largely eliminates the dependence upon the early abundances of Uranium and Thorium." Therefore the age usually given for the hardening of the earth's crust, 1-2 x 109 years, will be essentially uneffected by the early U236. Helium methods are used in meteorite age determinations, and these methods would need revision if the age appeared to be more than a billion years.

In view of the scientific Christians' interest in general cosmological problems, I thought it worth while to bring this article to the attention of ASA members.

No real change in the geologic time scale is introduced by these considerations, but some modifications in theories of early earth history may be in order, giving a little more insight into God's methods of creation of the heavens and the earth.

I would also like to lend my support to a principle stated by J. C. Sinclair in the ASA Journal, September 1953 issue, page 11, under the heading "ASA Publication Policy". A wider distribution of shorter articles relating science and the evangelical Christian theological position is a more efficient way to demonstrate to the public that Christianity is a reasonable and necessary point of view. Various monographs and reprints may be widely circulated through the ASA. Probably the editorial board of the Journal should select and clear these before official release, to insure sound scholarship. Distribution through individual members might be accomplished by mailing a copy of each selected short article to each member, and allowing members to order copies as they desire and can use them in their individual witness and in church work.

ASA members ought also to consider writing for such magazines as His of IVCF, Young Life Magazine, Christian Herald, and others. In this way sound scientific support for evangelical Christianity may be brought to a larger number of people than the Journal readers. 

Radiological Laboratory
University of California Medical Center
San Francisco 22, California