Science Frontiers
The Unusual & Unexplained

Strange Science * Bizarre Biophysics * Anomalous astronomy
From the pages of the World's Scientific Journals

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About Science Frontiers

Science Frontiers is the bimonthly newsletter providing digests of reports that describe scientific anomalies; that is, those observations and facts that challenge prevailing scientific paradigms. Over 2000 Science Frontiers digests have been published since 1976.

These 2,000+ digests represent only the tip of the proverbial iceberg. The Sourcebook Project, which publishes Science Frontiers, also publishes the Catalog of Anomalies, which delves far more deeply into anomalistics and now extends to sixteen volumes, and covers dozens of disciplines.

Over 14,000 volumes of science journals, including all issues of Nature and Science have been examined for reports on anomalies. In this context, the newsletter Science Frontiers is the appetizer and the Catalog of Anomalies is the main course.


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Subscriptions to the Science Frontiers newsletter are no longer available.

Compilations of back issues can be found in Science Frontiers: The Book, and original and more detailed reports in the The Sourcebook Project series of books.


The publisher

Please note that the publisher has now closed, and can not be contacted.

 

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... Science Frontiers ONLINE No. 9: Winter 1979 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Tarnished halos?Pleochroic halos are dark rings of various radii seen in mica and other minerals. There is general agreement that alpha particles emitted by radioactive isotopes create the halos. The radii of the rings are proportional to the alpha particle energy, and can thus identify the isotopes in the mineral. Some halos, however, are apparently formed by very short-lived polonium isotopes without any trace of parent uranium isotopes. How can polonium isotopes with half-lives only seconds long get into geologically old mica sans parents? York argues the case for selective local chemical concentration of polonium from fluids in the surrounding rocks. The captured polonium atoms decay almost immediately ... Science Frontiers ONLINE No. 9: Winter 1979 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Tarnished halos?Pleochroic halos are dark rings of various radii seen in mica and other minerals. There is general agreement that alpha particles emitted by radioactive isotopes create the halos. The radii of the rings are proportional to the alpha particle energy, and can thus identify the isotopes in the mineral. Some halos, however, are apparently formed by very short-lived polonium isotopes without any trace of parent uranium isotopes. How can polonium isotopes with half-lives only seconds long get into geologically old mica sans parents? York argues the case for selective local chemical concentration of polonium from fluids in the surrounding rocks. The captured polonium atoms decay almost immediately ...
Terms matched: 2  -  Score: 258  -  15 May 2017  -  URL: /sf009/sf009p11.htm
... boron. Occasionally, they harbor tiny radioactive impurities; usually alpha-particle emitters in the uranium-238 decay chain. Alphas emitted by these impurities have well-defined energies and penetrate the diamond matrix only so far. If one examines a diamond with a high-power microscope (say, at 100 x), one can see concentric rings surrounding the impurities. These dark radiohalos or "pleochroic" halos have specific radii and can be used to identify the radioisotopes that produced them. So far, so good; but: "The fact that fully formed, optically visible internal radiohalos in diamonds are now presented casts a considerable shadow over current theories of diamond genesis." Actually, the radiohalos pose three challenges to diamond-genesis theory. Problem 1. The half-lives of ... halo-creating radioisotopes are measured in thousands of years rather than the billions prescribed for crystallization. In fact some of the half-lives are only minutes or days long. M.H . Armitage comments: "How could these halos become imprinted if the formative cooling processes involved require such lengthy intervals?" Problem 2. The radioactive impurities producing the radiohalos are very tiny -- about 2-4 micrometers in diameter -- and are highly concentrated. Armitage continues: "What is most difficult to understand is that many of these inclusions and impurities have much lower melting and boiling points than the diamonds in which they are found." Why did the impurities fail to disperse as the higher-melting-point diamond matrix surrounding them slowly cooled down the eons? Photomicrograph (100x) ...
Terms matched: 2  -  Score: 242  -  15 May 2017  -  URL: /sf092/sf092g09.htm

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