Extended Peer Review and Controversy

I realized my 1967 report in Nature on polonium halos had not settled the question of their origin in the eyes of my scientific colleagues. To more accurately test whether polonium halos were of secondary origin, I needed a method that would allow me to determine whether uranium solutions had ever passed through a specimen of mica. A newly discovered technique made this evaluation possible. It was based on the fact that an atom decaying by alpha emission leaves a very tiny damage pit when the nucleus of the atom recoils into the mica. By etching the mica with acid, these tiny pits could be enlarged sufficiently to become visible under the microscope. Thus, any uranium solution which might have supplied radioactivity for polonium halos in a piece of mica, must also have produced numerous additional recoil pits from those radioactive atoms which decayed in transit. (All mica specimens have a background density of damage pits from trace amounts of uranium.) On this basis the mica specimens containing polonium halos should have a higher damage-pit density than the adjacent areas which are devoid of polonium halos. However, a long series of experiments showed no difference in the density of damage pits between the two specimens. [p. 41] These experiments provided evidence against the secondary origin of polonium halos in mica.

I wrote up these new results and submitted them for publication in Science, a journal with an outstanding reputation among all scientific disciplines. My first draft, submitted in May 1967, concentrated on the experimental results and contained only oblique reference to any implications. As usual, two anonymous referees were chosen to review the manuscript. Referee A approved the manuscript. Referee B wanted more explanation about how polonium halos in granites had originated. My revised manuscript was somewhat more explicit, for I suggested that

the experimental evidence indicates the inclusions of the polonium halos contained the specific alpha emitters responsible for the halos (or possibly in certain cases beta decaying lead precursors) at the time when the mica crystallized, and as such these particular halos represent extinct radioactivity.

Reviewer B objected to this statement, claiming that I had proposed a "very weak and contradictory argument," and said the manuscript should not be accepted. However, since this referee had not criticized the experimental data, I had the opportunity to ask for further consideration. After some discussion with the editorial office, it was agreed that the manuscript could be revised and that different referees and D) would be selected.

My next revision avoided direct references to the contradiction which polonium halos in granites pose to the conventional view of earth history. Instead the implications were phrased in the form of a series of questions. After some delay, I learned referee C had approved this revised manuscript. My hopes were high that referee D would do likewise.

Soon I received another letter from the editorial office, stating that referee D had raised some serious questions which had to be answered before the article could be published. Reviewer D had made some penetrating observations about the possible meaning of my results: Did they suggest a radically different model for the origin of the earth? Part of his review reads as follows:

Gentry proposes in this and previous papers that "extinct radioactivity" is responsible for halos whose "parents" are polonium and/or lead isotopes with half-lives ranging from 3 minutes to 21 years, and it is clear that he means "extinct natural radioactivity" by his statements that "the inclusions of the polonium halos contained the specific alpha emitters responsible for the halos (or possibly in certain cases beta decaying lead precursors) at the time when the mica crystallized," and "it is not clear just how the existence of short half-life radioactivity may be reconciled with current [p. 42] cosmological theories which envision long time spans between nucleosynthesis and crustal formation." Does he mean to imply that current cosmological (and geological) theories are possibly so wrong that all of the events leading from galactic, or even protosolar, nucleosynthesis to the formation of crystalline rock minerals could have taken place in a few minutes?

Of course the answer was yes! It was gratifying to see the experimental data spoke so loudly that the implications of polonium halos as extinct natural radioactivity could not be overlooked. Figure 2.4(a) illustrates the evolutionary meaning of extinct natural radioactivity and Figure 2.4(b) illustrates the creation implications of polonium halos as extinct natural radioactivity. Despite evidence to the contrary, referee D concluded that Henderson's model of secondary polonium halo formation must somehow be correct. The tenor of his comments made it seem futile to request further consideration of my manuscript. Yet one aspect of his response compelled me to persevere.

A seldom violated rule of the peer review process is that the scientists who act as referees remain anonymous to the authors of the submitted manuscripts. But this reviewer actually requested the editorial office to make his name and address known to me. On the reviewer's statement form he even invited me to contact him directly. Encouraged by his frankness, I telephoned him immediately.

At the very outset of this first conversation he asked my opinion of the implications of polonium halos in granites. Such a direct question deserved an equally direct response. I replied that they seemed to be evidence for creation. Surprisingly enough, he didn't hang up! Instead, this world-renowned authority in radiometric dating continued to ply me with incisive questions over the next hour. At the end of the conversation he was sufficiently impressed with the evidence to suggest that certain other experiments be conducted to enable him to further evaluate the implications of my work. These additional experiments required research equipment not available at Columbia Union College.

Initial Experiments at Oak Ridge

A search for the necessary facilities led me to inquire at the Oak Ridge National Laboratory in Oak Ridge, Tennessee. Years before, while I was still in Atlanta, a staff scientist, Roger V. Neidigh, had kindly assisted in getting some experiments done at this outstanding research complex. I was again extremely fortunate that another Laboratory scientist, John W. Boyle, took a personal interest in arranging for the additional experiments then [p. 43] needed. Without his cordial and very able cooperation they could not have been done.

With the results of these new experiments and a newly revised manuscript in hand, I visited referee D at his own laboratory. This fair-minded colleague made an exhaustive study of the new results and concluded that polonium halos in granites were more perplexing than he had first thought to be the case. The lack of evidence to support the hypothesis that they originated from some secondary source of uranium puzzled him. He indicated a willingness to consider this revised manuscript for publication provided there was no mention of the possibility that polonium halos may have originated with primordial polonium. This report, "Fossil Alpha-Recoil Analysis of Variant Radioactive Halos," was subsequently published in the June 14, 1968, issue of Science (Gentry 1968; Appendix—this notation indicates the report cited is also reprinted in the Appendix).