Steven Dutch, Natural and Applied Sciences, Universityof Wisconsin - Green Bay
First-time Visitors: Please visit Site Map and Disclaimer. Use"Back" to return here.
I will respond to questions and comments as time permits, but if you want to take issuewith any position expressed here, you first have to answer this question:
What evidence would it take to prove your beliefs wrong?
I simply will not reply to challenges that do not address this question. Refutabilityis one of the classic determinants of whether a theory can be called scientific. Moreover,I have found it to be a great general-purpose cut-through-the-crap question to determinewhether somebody is interested in serious intellectual inquiry or just playing mind games.Note, by the way, that I am assuming the burden of proof here - all youhave to do is commit to a criterion for testing.It's easy to criticize science for being "closed-minded". Are you open-mindedenough to consider whether your ideas might be wrong?
Much of the color of materials is due to the way light interacts with the electrons in the material. If a photon of light matches a possible energy level of an electron, the light can be absorbed. Electrons close to the nucleus are so tightly bound that visible light doesn't have enough energy to affect them. Their energy levels are out of reach. In solids, the outermost electrons of atoms have either been stripped off or shared with other atoms. Most of the remaining electrons are paired up, and visible light doesn't have enough energy to raise them to a higher energy level.
In order to interact with visible light, there have to be loosely-held, unpaired electrons in the material. Of the commonest elements in minerals, only iron has unpaired electrons, and therefore iron is far and away the most important cause of color in rocks, minerals and soils. Less important sources of color include manganese, organic chemicals, and copper. Elements that cause color in minerals are mostly metals in the center of the Periodic Table.
There is another way of creating unpaired electrons and that is to let them occupy an empty space in the material where an atom should be, or settle into open spaces between atoms. Sometimes these vacancies form while the material itself is forming. However, radiation is a very good way of knocking atoms out of position and dislodging electrons. Since these electrons are not tightly bound in place, they are free to interact with light. Diamonds and other gems are commonly irradiated to change or improve their color. Often heating destroys the colors created by these free electrons by causing the material to recrystallize in its proper structure, or knocking free electrons out of position. Heating gemstones sometimes bleaches out colors.
It very often happens that tiny inclusions of radioactive minerals will produce radiation damage visible under the microscope. Uranium, thorium and their decay products give off alpha particles (helium nuclei) that plow through the mineral like a bull in a china shop, creating abundant free electrons and damage sites for them to occupy. So these minerals will be surrounded by dark haloes. Also, when viewed with polarized light, the color will vary depending on how the mineral is oriented compared to the polarization. As you rotate the specimen under the microscope, it changes in color. Typically the specimen changes from darker to lighter and back. This behavior is called pleochroism, and radiation haloes around mineral inclusions are thus called pleochroic haloes.
Irish geologist and mineralogist John Joly first proposed in 1907 that pleochroic haloes were caused by radioactivity, which at that time had only recently been discovered. Beginning in 1968, Robert V. Gentry, then a visiting researcher at Oak Ridge National Laboratory, began publishing articles on pleochroic haloes. Over the next ten years, Gentry published articles in leading scientific journals like Science and Nature in which he identified many haloes as due to radiation given off by specific elements. It is possible to identify the causes of specific haloes because many have concentric rings whose radii are proportional to the energies of the emitted particles. Oddly, some haloes seemed to be associated solely with the short-lived element polonium.
In Gentry's own book, Creation's Tiny Mystery, he reveals that he had creationist leanings early in his research and became convinced that the short lifetime of polonium must mean that the minerals enclosing the haloes had formed almost instantaneously. He describes a number of papers he submitted which were rejected because of comments about the haloes constituting a "challenge" to cosmology. As Gentry said of one paper (all quotes are from the on-line version of Creation's Tiny Mystery):
Soon afterward I submitted my experimental results on polonium halos for publication to the same journal. Near the end of the manuscript I included the following suggestion about the origin of polonium halos:
. . . It is difficult to reconcile these results with current cosmological theories which envision long time periods between nucleosynthesis and [the earth's] crustal formation. It is suggested these [polonium] halos are more nearly in accord with a cosmological model which would envision an instantaneous fiat creation of the earth.
I had been naive enough to think that something this straightforward might pass peer review. It didn't.
"Naive" hardly begins to describe it. Let's for the moment admit Gentry's assumption that science should drop everything and re-examine its most basic findings every time someone claims to see a contradiction. What Gentry has, at best, is evidence that minerals accumulated polonium before it had a chance to decay. That's a long way from a challenge to cosmology. Strictly speaking, assuming Gentry is right about halo formation, all he has is evidence that a mineral grain formed quickly enough to trap polonium and record a halo. That shows only that a mica grain a few millimeters in diameter crystallized within a few days, not that an entire granite intrusion solidified within a few days, still less that there is something fundamentally wrong with cosmology.
This is a classic example of what has been called "naive falsification," the notion that a single anomaly, no matter how poorly documented or interpreted, can suffice to undermine even the best-demonstrated concepts in science. Well known examples in the history of science include physicist Dayton C. Miller's failure to replicate the Michelson-Morley experiment, and Immanuel Velikovsky's claims that catastrophe legends refuted the idea that the planets have had stable orbits during the geologically recent past. In most cases believers in naive falsification jump immediately from the anomaly to the most sweeping possible interpretation of it without looking for alternative explanations first. In the case of Miller and Velikovsky, the alternative explanation is that they were simply wrong. In Gentry's case we can be a bit more charitable.
We can sum up Gentry's chain of reasoning thus:
How much polonium will there be? A decay chain reaches equilibrium when the number of parent atoms that decay per unit time equals the number of daughter atoms that decay per unit time. In other words, decays of parent atoms replace the lost daughter atoms. In terms of half life, (Parent Atoms)/(Parent h.l.)=(Daughter Atoms)/(Daughter h.l.) Polonium 210 forms from the decay of Uranium 238, which has a half life of 4.5 billion years, and Polonium 210 has a half life of 138 days. So for every Po-210 atom there should be (4,500,000,000x365)/138 = 12 billion U-238 atoms. Granite is about 5 parts per million uranium, so in a cubic kilometer of granite magma (weighing 2.5 trillion kilograms) there will be 12.5 million kilograms of uranium - 12,500 tons - and about a gram of polonium - all the time, or at least until the uranium decays away.
By the late 1970's, Gentry's research funding was beginning to dry up. In 1977 one of his proposals was rejected with the comment:
The principal investigator has been collecting specimens, examining them petrographically, and reporting their morphology and mineral occurrence for a number of years. The panel considered that these descriptive contributions have been of some value, but felt that more of the same approach had little [p. 77] potential to contribute something new. The main difficulty with the proposal is that (aside from the superheavy element search) there was no hypothesis concerning the origin of the haloes that the principal investigator proposed to test. He has already looked at and described a number of occurrences. The panel felt that it was not justified in recommending funding of a research project that merely proposed to make additional observations of the phenomenon. There seems little possibility that the principal investigator could arrive at a hypothesis by looking at additional haloes since he has not been able to propose one at this time.
In his appeal, Gentry wrote:
I specifically refer to the fact that I have proposed that "Po halos" in Earth's basement granitic rocks represent evidence of extinct natural radioactivity and thus imply only a brief period between "nucleosynthesis" and crystallization of the host rocks [Gentry 1975]. . . . Furthermore, back [p. 78] in 1973, again in a Nature report [Gentry et al. 1973], I pointed out the existence of Po halos "meets with severe geological problems: the half-lives of the polonium isotopes (t = 3 min for 218Po) are too short to permit anything but a rapid mineral crystallization, contrary to accepted theories of magmatic cooling rates." . . .
In fact a person really doesn't have to be a geochemist, or even have training in geochemistry (actually I am a physicist turned aside into nuclear geophysics), to see that in my published reports I am claiming to have found evidence that shakes the foundations of modern cosmology and geochemistry.
There's a huge difference between proposing something and proving it. And Gentry persistently refuses to deal with the likelihood that the polonium derives from the decay of uranium and thorium. Gentry's appeal was turned down. Gentry comments:
In this response, Dr. Todd ignored the three main points of my appeal letter: (1) NSF support of the other researchers who participated in the original superheavy element experiments, while denying similar support for my research; (2) the panel's refusal to acknowledge that I had proposed a hypothesis for the origin of polonium halos; (3) my claim of finding evidence which challenges the foundations of modern cosmology and geochemistry.
Taking his comments in order:
All in all, the excerpts Gentry provides give the impression that he was treated with velvet gloves compared to the pounding other scientists routinely get from reviewers.
Even while the controversy over haloes was raging, the solution to the problem was actually already published. One paper that supplied the answer wasNatural annealing of pleochroic haloes in biotite samples from deep drill holes, Fenton Hill, New Mexico, by Randy Laney and A. William Laughlin, published in Geophysical Research Letters, Volume 8, Issue 5, p. 501-504 (May, 1981). The abstract, in its entirety, is below:
Examination of 46 thin-sections of Precambrian metamorphic and igneous rocks from three deep drill holes in northern New Mexico reveals a narrow depth-temperature range for annealing of pleochroic haloes in biotite. Annealing of the haloes is first observed in samples from a depth of 1850 m (134C present temperature) and is complete in samples from a depth of 2120 m (151C). The observed temperature of annealing of the haloes is in good agreement with earlier observations of fission track annealing in apatite from the same core samples.
The real reason pleochroic haloes don't prove that granite cooled abruptly is startlingly simple: pleochroic haloes cannot survive in hot rocks. Heating both dislodges free electrons so they can return to their original locations, but also causes minerals to recrystallize (anneal) and heal damage. This, of course, is a violation of the Creationist Second Law of Thermodynamics, which asserts that order can never arise spontaneously, except that metallurgists use annealing all the time.
Since pleochroic haloes don't endure in hot rocks, their existence proves nothing about the formation of the rocks.
Gotcha! replies the creationist. Not only did the rocks form instantly with polonium already incorporated, but they formed cool. And your evidence is...? The rocks from the New Mexico study had haloes near the surface but lost them by the time the subsurface temperature was about 150 C. So we'd have to postulate that the present surface in New Mexico is the primordial surface of the earth.
Return to Pseudoscience Index
Return to Professor Dutch's Home Page
Created 04 February 2008; Last Update 24 May, 2020
Not an official UW Green Bay site