polonium halos

Tranquility Base said:
With the recent helium retention work creationists are now accepting all of the radiodecay data (finally!) and now we can start looking back at Gentry's stuff again. The halos document that (i) radiodecay occurred but that (ii) it was accelerated. I believe that claims that all of Gentry's stuff was refuted in the 1980s are exaggerated, but I am not an expert.Gentry’s work with polonium halos is based on the premise that rates of radioactive decay have been constant. If decay rates have varied, then his work is invalidated. He identified the halos in his biotite samples based on the diameter of those halos, which he said is directly proportional to the energy of the decay of the isotope that formed the halo (the greater the energy the larger the halo). He said that the energy released by the decay of particular isotopes of polonium would form halos with the same diameter as the halos in his samples, and therefore that the halos in his samples formed through the decay of polonium. If radioactive decay rates have changed, then the energy associated with the decay events has changed, and if that’s the case his identifications are invalid.There are major problems with Gentry’s work. For example, the isotopes of polonium that Gentry proposes for his halos (Po 210, 214, and 218) are all part of the decay series of uranium238, and there are uranium-bearing minerals in the rocks where he collected his samples in Ontario. So, contrary to Gentry’s claim there is a source for the polonium in his samples. Further, Po210, 214, and 218 all occur after radon222 in the decay series, and since radon’s a gas, not only is there a source for the polonium, there’s a source that’s capable of migrating through the rocks where he collected his samples.Richard Wakefield’s analysis of Gentry's work:
Tiny Mystery Home Page

Tranquility Base:
Not necessarily. The pop-out rate may change but the energies may stay the same. This may or may not be possible and we await the RATE guys theoretical work. Regardless, Gentry's creation granite may be at a time point during normal decay rates.That’s an interesting idea, but it’s unworkable since half-life and kinetic energy are related; if you change one, you change the other. If you want the isotope to decay faster you’d have to reduce the half-life, which would increase the kinetic energy, and therefore the diameter of the halo.The relationship between kinetic energy and the half-life are discussed here.
http://www-highspin.phys.utk.edu/~bingham/AlphaDecay.htmlTranquility Base:
It's possible that Gentry's stuff is wrong, I agree. I don't kow enough about it and I hope you understand that I would like to read his rebuttals (anybody know if they are on the web?).I can certainly understand your desire to read Gentry’s work. I don’t know what he’s published on the web. I don’t know of any valid rebuttals for the problem that I mentioned, as well as others (for example the fact that his halos occur in igneous dikes in metamorphic rocks, and are therefore younger than the metamorphic rocks, and therefore cannot be Genesis rocks). You can read Gentry’s responses to some problems on his website Evidence for Earth's Instant Creation - Polonium Halos in Granite and Coal - Earth Science Associates

Tranquility Base:
Your link states that the half life is dependent on Q (the KE release) but it may be dependent on other things. It actually poinys out that you can get 24 orders of magnitude half life change from a doubling of Q so maybe the 6 orders of magnitude change in half-life we are talking about could even use a small Q change. I'm an ex- particle physicist but I'll take a look at the RATE book before wasting too much time on it.The half-life may certainly be dependent on other factors, but I still don’t see how you can change the half-life without changing the kinetic energy release, and therefore the halo diameter. With that said, I’m not a physicist, and if you know of such a way, I’d love to see it.I suppose that the point you’re trying to make is that you don’t need much of a change in Q to get a big change in half-life. It seems that you’re arguing that perhaps Q changed enough to result in a big change in the half-life but not a measurable change in the halo diameter. I don’t think that’s a workable idea. From the reprints of Gentry’s papers available on his website or in the appendix of his book (these data are from his 1968 (not available on his web site) and 1973 papers):Isotopes of polonium:Isotope-alpha particle kinetic energy-Half-life-Halo radius218Po-6.0MeV-3.0min-23micrometers
214Po-7.69MeV-164microseconds-34micrometers
210Po-5.30MeV-138days-19micrometersThe difference in alpha particle kinetic energy between 210Po and 218Po is 0.7MeV, an increase of 13%, and the difference in half-lives is 5 orders of magnitude. The difference between 218Po and 214Po is 1.69MeV, an increase of 28%, and the difference in half-lives is 6 orders of magnitude. Based on these data, it seems that changing the decay of Po by six orders of magnitude will result in measurable differences in the size of the halos, even assuming that such a change were possible.Based on the alpha particle kinetic energy of the isotopes in the decay series of 238U that Gentry lists in the 1973 paper, isotopes that differ by as little as 0.1MeV produce halos that are far enough apart to be optically resolvable. This seems to me to indicate that even very small changes in the kinetic energy release will result in measurable differences in the halo size.Tranquility Base:
I've actually got Gentry's 1980s book. On the halo.com site he is certainly claiming that the 'refutations' are invalid.I picked up a used copy of Gentry’s book a while back. I wasn’t trying to dismiss his refutations in my previous post, but I was trying to put off a discussion of them until after you’d read his work.The refutations by Gentry that I can find are:
Page not found – Creation In The Crossfire
and
http://www.halos.com/finger.htmOne of the problems with Gentry’s work that I pointed out is that his rocks are from younger dikes emplaced in an older rock, and so dikes cannot be Genesis rocks since the physical relationships indicate that the metamorphic rocks are older than the halo-bearing dikes. One of the refutations that Gentry makes to this is that the age relationships are based on radioisotope dating, which he dismisses (which in fact, if true, would invalidate his work for reasons we’ve been discussing). He also attempts to refute the problems caused by the age relationship of the dikes with the metamorphic rocks by saying that they’re both creation rocks, and that the metamorphic rocks were created earlier in the creation week than the dikes. The biggest problem here is that this ignores the history recorded in the metamorphic rocks. The metamorphic rocks did not start out as metamorphic rocks, they were metamorphosed when they were subjected to intense heat and pressure. In some cases it’s still possible to see what the parent of the metamorphic rock was, it’s possible to identify what type of rock the metamorphic rock was before it was metamorphosed. There are still recognizable pillow basalts near the locations in Ontario where Gentry collected his samples. This indicates that these rocks initially formed as basalts that were erupted underwater and were later subjected to heat and pressure to form the metamorphic rock that exists today. In fact, the rocks in the Bancroft area record several different episodes of deformation and accompanying metamorphism. Gentry can attempt to dismiss these problems as uniformitarian assumptions, but that just ignores these problems.Another refutation that I’ve encountered is that it’s not possible to make granite in the lab, and this indicates that the formation of granite requires miraculous creation. The biggest problem with this claim is that not all granites are Precambrian, there are granites and granitic rocks that are quite young. For example the large granitic intrusions in the Bingham canyon copper mine in Utah (the largest or perhaps second largest open pit mine in the world — an irrelevant but interesting bit of trivia), are Tertiary. This is not indicated by radioisotope dating (although radioisotope dating does confirm this), it is indicated by the fact that these intrusions cross-cut pre-Tertiary rocks, and so the intrusions are younger than those rocks. In fact there are huge inclusions of these pre-Tertiary rocks (referred to as xenoliths, if you’re familiar with the term) in the intrusions that are 10s to 100s of meters long. Gentry can claim that the Tertiary age can be discarded because it’s based on uniformitarian assumptions, but that just ignores the physical relationships between the intrusion and the surrounding rocks, in no way does it invalidate the age. Quite clearly, granites cannot be remnants of the creation week.I’ll have to stop there for now, I’d rather sit here and type for the rest of the day, but I have to go to work. Thanks for the interesting discussions.

From Snelling’s article:
Furthermore, such accelerated radioactive decay would have generated a large pulse of heat during the Flood. This in turn would have helped to initiate and drive the global tectonic processes that operated during the Flood year, and to accomplish catastrophically much geologic work, including the regional metamorphism of sedimentary strata and the melting of crustal and mantle rocks to produce granitic and other magmas.The first problem here is that Snelling is missing the point that the halos aren’t compatible with the idea that radioactive decay was faster in the past. I think Snelling is also significantly underestimating the amount of heat the would be generated by accelerated radioactive decay, as Joe Meert has previously pointed out:
ROASTING ADAM-Creationism's Heat ProblemFrom Snelling’s article:
The implications are far-reaching. Because the half-lives of these Po isotopes are very short, the hydrothermal fluid transport had to be extremely rapid. The hydrothermal fluids are generated as the granitic magmas cool, so the timeframe for the cooling of these granitic magmas has to have been extremely short (only days!) as the expelled hydrothermal fluids also carried away the heat.The short half-lives of the polonium isotopes do not indicate that the granite cooled in a matter of days. This seems to me to be a move toward Gentry’s original premise that the short half-lives of the polonium isotopes indicate that the granites formed in a matter of microseconds. The half-lives are not related to the time it takes the granite to crystallize. All that’s required for polonium halos to form is for a source of the polonium to move through the rocks (as I discussed earlier radon-222 looks like the most likely candidate). As I mentioned in my first post, the area where Gentry collected his samples in Ontario is very rich in radioactive minerals. Since radioactive decay is still occurring in this rocks, Rn-222 is still being generated, and so there is still a source of polonium moving through the rocks there. I also don’t see how the presence of polonium halos provides any information about the cooling history of the igneous rocks that contain them since the halos can form at any time after the rock has cooled.I understand that the article you linked to is most likely only a brief summary of Snelling’s thoughts on polonium halos. If/when he provides more detailed information, I’ll be happy to take it into account. However, based on this article Snelling’s claims about the implication of the occurrence of polonium halos are not workable. I am encouraged to see that Gentry’s arguments are being discarded, however based on this article, I do not think Snelling’s are any more supportable.