Answers in Genesis Gets it
Wrong on Star Formation
Tim Thompson
Creationists have argued that primordial stars cannot form, and that stars are not forming in the universe now. We are led to two primary sources, both hosted by Answers in Genesis.
The first of these, Stars Could Not have Come from the Big Bang, which has no author credited to it, makes the assertion that primordial gas clouds are "a hundred times too hot to collapse". There is no reference to a source to support this contention, and no sample calculation is given. However, the short piece finishes with an elegant quote: "The truth is that we don't understand star formation at a fundamental level." This is attributed to Abraham Loeb (Department of Astronomy, Harvard University) with citation to a 1998 article in New Scientist, a well known British publication, that concentrates on news and opinion pieces and a few popular reviews. Taken out of context, it's hard to know what Loeb really means, and that, of course, is the reason why the quote is provided without context. After all, the fact that we do not understand gravitation at a fundamental level does not mean that we cannot use both Newton and Einstein to describe the workings of gravitation in considerable detail. Likewise, even though we do not understand star formation at a fundamental level, this certainly does not mean that we know nothing. It does not mean that we cannot apply relevant physics to the solution of the problem.
Perhaps we can better understand what Prof. Loeb really has in mind by looking at what he has written about star formation. For instance, In the Beginning: The First Source of Light and the Reionization of the Universe, currently in preprint form, is destined for the pages of Physics Reports. It's a 136 page review of the physics of the infant universe, including the formation of primordial stars, by Rennan Barkana, currently at the Canadian Institute for Theoretical Astrophysics, and Loeb.
This paper demonstrates that the true context of Loeb's comments is rather different than Answers in Genesis would have you believe. First, we know that primordial stars, and non primordial stars, can and do form. Second, the assertion that clouds are "a hundred times too hot" to form stars is directly refuted by the analysis that appears in section 3.3, "Molecular Chemistry, Photo-Dissociation, and Cooling", as well as chapter 4, "Fragmentation of the First Gaseous Objects". The Jeans mass is about 30,000 solar masses, and will fragment to form an accreted hierarchy, but the cooling mass limit is higher, about 500,000 solar masses. This means that, as presumed, the first primordial stars were very massive by the standards of star formation we are now used to. But the clouds are not too hot to collapse, as Answers in Genesis suggests.
It would seem that the short and unattributed Stars Could Not have Come from the Big Bang is simply a propaganda piece of no intelligent value or content (a feeling reinforced by the evidence that no one wishes to be cited as author). However, the other entry from Answers in Genesis has an author: Are Stars Forming Today?. This is a "creation question", answered by Dr. Ronald G. Samec, who appears to not have a biography posted at Answers in Genesis; he may have been on the faculty of Astronomy and Physics at Millikan University, but is not there now. [see footnote]
Samec faces the question posed: "The Hubble Space Telescope (HST) has recently taken some spectacular pictures of stars forming. Doesn't this prove that stars were not created?" The reference is to the HST images of the Eagle Nebula (M16).
Samec says, "I presume that the temperatures of these areas are near 10,000 K so that they glow like the surfaces of stars of similar temperature, that is, white. Gas at such temperatures will quickly disperse and there is no chance of it forming stars. We should not be convinced that embedded stars exist within the 'finger tips' of these dust regions unless they are actually imaged." [Italics are Samec's]
Recent observations with NIRSPEC, an infrared spectrometer on the Keck telescope, reveals temperatures in the photodissociation region of 9500 K, not far from Samec's guess of 10,000 K. But that's for the hot halo gas. The same data show a molecular hydrogen temperature of 930 K, far below Samec's guess. ("Hot stars and cool clouds: The photodissociation region M16" N.A. Levenson et al., Astrophysical Journal 533(1): L53-L56, April 10 2000).
Observations with ISOCAM (an instrument on the Infrared Space Observatory) show even lower temperatures, about 250-320 Kelvins, in the main nebular cloud ("ISOCAM images of the 'elephant trunks' in M 16", G.L. Pilbratt et al., Astronomy and Astrophysics 333(1): L9-L12, May 1 1998).
Observations of molecular emission from the dense dust knots reveal the gas to be a "surprisingly warm" 60 K, while the dust is as cool as 20 K. Furthermore, model simulations of the earliest stages of star formation produce results that look just like what is actually seen in the Eagle Nebula ("The Eagle Nebula's fingers - pointers to the earliest stages of star formation?", G.J. White, et al.", Astronomy and Astrophysics 342(1): 233-256, February 1999).
In this case Samec's intuition turns out to be quite wrong. His 10,000 K turns out in reality to be as low as 20-60 K. How did Samec manage to miss by over 9000 K? Wishful thinking, I suppose: any professional astronomer really should have known that star formation would take place inside the dense clouds (just like the press release says) and that the temperature there could not be anywhere near 10,000 K (as observation has confirmed). Yet he went out of his way to emphasize (remember, the italics in my quote are from Samec's original) "there is no chance of star formation". In my considered opinion, only a strong, wishful bias can explain such poor judgment.
Both Samec and Anonymous have proven to be less than reliable purveyors of information regarding star formation. But the Eagle Nebula images, as spectacular as they are, are not the only star formation show in town. Indeed, the venerable Hubble has done far better, if it's star formation you want to know about. Astronomy 122: Birth and Death of Stars is a University of Oregon class for non science majors, delivered entirely over the Internet. The lectures are well illustrated, especially lecture 14, "Star Formation". There you will find illustrations of how the basic theory of star formation has long been known to work; a collapsing, rotating cloud produces a flat disk, and eventually axial jets form, primarily because the protostar wind is blocked by the equatorial disk, though magnetic field focusing plays a role as well.
Look at the lecture diagrams first, and then look at the HST images of "proplyds" in the Orion Nebula, and the HST Orion Nebula Mosaic. You see disks, as expected, with protostars in the middle, as expected. Even better, look at Hubble Observes the Fire and Fury of a Stellar Birth, where we see disks and the predicted axial jets. The time lapse image of HH-30 shows that you can see the motion in the axial jet. That motion has even been turned into a movie.
Blind assertion and wishful thinking simply don't cut it in a field dominated by science. Samec guessed at temperatures over 10,000 K to prevent star formation because he allowed his wish that it be that way to cloud his judgment that it could not be that way. Observation proved him wrong. Anonymous tried to trick the reader into thinking that a respected astronomer was admitting some deep weakness in astrophysics, when in reality he was just making a simple observation that all theories are "not understood at the fundamental level", since there is no such thing as a scientific theory that can boast of perfection.
Science may not be perfect, but it is consistent. It is absurd, and no other word will do, to argue that star formation does not or cannot happen, unless you can demonstrate why the images here are not images of star formation, and unless you can demonstrate why the physics that leads inevitably to star formation is wrong. Word games and quote mining won't do, objections have to be quantitative and valid.
I maintain that there are no valid creationist objections to star formation, primordial or otherwise. Simple physics leads inevitably to star formation.
On my criticism of Samec's Are Stars Forming Today?", I have been told that I have misrepresented Samec, to the extent that the 9500K temperature reported by NIRSPEC was for the same area that Samec was talking about, where he guessed 10,000 K, namely the hot, glowing gas halo around the dust clouds, which stands out so well in the Hubble Images.
I certainly never intended to misrepresent what Samec says, and didn't think I was. In fact, I had thought about that same point myself, but rejected it for a simple reason. Nobody thinks that star formation takes place in the gas halo, it takes place in the dense knots of dust clouds. Just look at the "EGG" drawing on the Hubble page, which clearly shows that the gas halo is not where they expect to see stars forming. So if that's really what Samec meant, then his comments are irrelevant to the issue. What good does it do to criticize a theory of star formation which nobody believes anyway? I concentrated on the low observed temperatures in the dust, because that's where astrophysicists think stars form, and observation shows that the high temperature argument Samec give does not operate in those regions.
Tim Thompson
