Supernovas in the Milky Way Galaxy
A question was sent to us regarding the existence or non-existence of third stage supernovas in our Galaxy. It has been claimed by several creationist organizations that there are no third stage supernovas in the Milky Way Galaxy. One reader saw that the TalkOrigin website had disputed this and the reader wanted to know what the truth was. The following is Barry Setterfield’s response. We appreciate your problem. However, although we have learned in general not to trust TalkOrigin, the fact is they are correct on this one. You probably got your information regarding the idea of no third stage supernovas in our galaxy from a Sarfati article [3]. He referenced an article by Keith Davies [2], which is where this claim seems to have originated. The main idea that Davies uses is that there is a value of 25 years for the rate of supernova occurrence in our galaxy. This estimate was made around 1970 by astronomer Gustav Tammann. In 1994, Tammann revised his 1970 estimate and, since then, there have been various estimates made regarding the rate of supernova occurrences. All of these estimates are calculated by comparing our galaxy with other similar galaxies, and working out the rate of supernova occurrence from them. However, therein lies a problem. Other galaxies may not be behaving in precisely the same way as our own galaxy, and there are different supernova rates in different galaxy types. There is an additional problem. Even among galaxies of the same type there are different proportions of stars which are suitable candidates for supernova explosions. Each galaxy is unique in this way. Therefore extrapolating from other galaxies to our own may not be advisable. It is at this point that we pick up on the study of supernova remnants done by Clark and Caswell [1], which is the primary paper referenced by Davies and thus secondarily referenced by Sarfati. In the first place, Davies actually is deceptive in the way he has quoted the Clark-Caswell article. In Section 10 of their article, Clark and Caswell are quoted by Davies as saying, “Why have the large number of expected remnants not been detected?” Davies then goes on to state that “these authors refer to ‘the mystery of the missing remnants.’” Davies has taken this quote out of its context, thereby implying that there is an unsolved problem. He then appears to have structured his entire paper around that quote. However, the quote from the Clark-Caswell paper runs as follows: “Thus, two anomalies require explanation. Why have the large number of expected remnants not been detected? Is it reasonable that E/n should differ so greatly from our estimate for the Galaxy? Both anomalies are removed if we assume that the relation has been incorrectly estimated owing to the small number (4) of remnants used.” They go on to say, “Since, according to our data, the Galaxy contains fifty SNRs brighter than this [numerical estimates given previous to this quote in the paper], it appears that the rate of occurrence in the Large Magellanic Cloud is smaller than in the Galaxy by a factor of 9/50, suggesting a mean interval of 830 yr.” They finalize this section of their paper by saying, “It appears that with the above explanation there is no need to postulate values of E/n differing greatly from those in the Galaxy, and the mystery of the missing remnants is also solved.” In their Section 11, which is their conclusion, Clark and Caswell say, “Completeness in the catalogue of SNRs to a uniform low level of surface brightness has permitted an improved estimate of SNRs in the Galaxy, which suggests that this number has previously been overestimated. A consequence of this conclusion is that the ‘characteristic interval’ between supernova events of a kind which produce typical remnants is about 150 yr – somewhat larger than previous estimates, but still comparable with the estimates of pulsar birthrates…and in agreement with estimates based on recent X-ray observations.” Therefore Davies was very dishonest in handling what had been said, and Sarfati evidently did not check the original article himself to verify what Davies had written and presented publicly. As young earth creationists ourselves, we find this kind of handling of other folks’ material deeply regrettable. There are, in fact, a number of third stage SNRs in our Milky Way Galaxy. The following abstracts list some of them: http://xxx.lanl.gov/abs/astro-ph/9812093 http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1986A%26A...163..185F&... http://adsabs.harvard.edu/abs/1995MNRAS.277..319D http://articles.adsabs.harvard.edu/full/gif/1986MNRAS.221..809R/0000809.000.html http://articles.adsabs.harvard.edu/full/gif/1995ApJ...439..722S/0000722.000.html
On this basis, it would seem that both Davies and Sarfati have either not checked the data that is available or ignored it. This is poor research at the best and deception at the worst. The final comment I would make is that the occurrence of supernovas is model-dependant. There is the standard model, which all the above papers, as well as the Davies and Sarfati papers reference, which states that stars beyond a certain size, in burning their fuel, build up various elements in their cores via fusion processes until they have come to the element iron. After the element iron has formed, the star is suddenly required to ‘pay back’ all the previous energy that has been expended. The only way it can do this is to undergo dramatic gravitational collapse, followed by an even more dramatic rebound which shatters the star and gives rise to the supernova explosion itself. There is another type of supernova involving a binary star system, but that is not what I want to discuss here. What I want to mention is that there is another basic model regarding supernova occurrences which is not considered in any of the above papers, but which is coming to the fore among a number of astrophysicists today. This is the model presented in Donald E. Scott’s The Electric Sky [4]. In it, and I am fascinated by his model which answers an number of outstanding problems, he states that stars are linked via plasma filaments to electric and magnetic fields within their respective galaxies. As a consequence of this, there are strong electric currents in the photospheres and upper layers of a star which cause the plasma which the star is composed of to radiate in arc current mode. The bluer the star, the higher the current. At the upper limit of stars’ masses, the current can be so high that the electrical stress on the star is such that it is only just holding together. If the electrical intensity of the current increases, it becomes sufficient to explode the star, thus resulting in a supernova. On that basis, the fluctuation of electric currents and magnetic fields within our galaxy, or any other galaxy, is the determining factor as to which massive stars explode, and when. Therefore the number of supernovas which occur in any given galaxy cannot be modeled, at least not with our present state of knowledge. It appears to be entirely in God’s hands, and this would include the future of our own sun, as well. Barry Setterfield, April 20, 2007 References: 1. Clark, D.H, and Caswell, J.L. “A Study of Galactic Supernova Remnants Based on Molonglo-Parkes Observational Data” Monthly Notices of the Royal Astronomical Society, vol. 174, 1976, pp 267-305 2. Davies, Keith, “Distribution of Supernova Remnants in the Galaxy” Proceedings of the Third International Conference on Creationism, Creation Science Fellowship, Pittsburgh, editor E. Walsh, 1994, pp 175-184. 3. Sarfati, Jonathan, “Exploding Stars Point to a Young Universe” Creation vol 19. no.3, June 1997, pp 46-48 4. Scott, Donald E. The Electric Sky (Mikamar Publishing, Portland, Oregon) 2006 |