Most, though not all, creationist organizations are committed to the belief that the universe was created no more than 10,000 years ago. In particular, this is true of the most vociferous one, the Institute for Creation Research (ICR), headquartered in San Diego, California. They apparently feel confident that rejection of evolutionary concepts is sufficient to invalidate all astronomical evidence for a great age of the universe. The following four arguments favoring a great age, three of which directly involve astronomy, do not in any way depend on evolutionary theory for their validity. On the other hand, at least the first two give strong support to the theory of stellar evolution.
Stars in a certain mass range eventually experience a cataclysmic event, known as a supernova explosion, in which most of their matter is blown away. Although current models of stellar evolution predict this event, our knowledge that it actually occurs comes, not from speculation, but from direct observation. An ordinary-looking star flares up, remains very bright for a few weeks or months, and then fades away to end up considerably fainter than it was originally. After the event, all that remains is a small dense remnant star surrounded by a cloud of expanding gas.
Probably the best-known example is the Crab Nebula, which is the remains of a supernova explosion observed and recorded by Chinese and others in 1054 A. D. It consists of an expanding gas cloud surrounding a small dense remnant star. The size and outward radial velocity of the gas cloud have been measured; the date for the explosion calculated from these measurements is in close agreement with the Chinese records. We find many remnants of other supernovae with larger and more tenuous clouds and with radial velocities indicating a much greater age than the Crab Nebula. For example, measurements on the Cygnus Loop indicate that this supernova explosion occurred approximately 60,000 years ago.
This result disproves the creationist timetable, and leaves only two alternatives: Either the expanding gas clouds we see are the results of explosions which occurred as much as 60,000 years ago, or some creator made these clouds appear old, and in fact created remnants of explosions that never occurred. Would this act have been carried out for the purpose of deceiving modern astronomers into the conclusion that the universe is older than 10,000 years? This alternative, i.e., a false appearance of great age, is of course always a possibility, and for easy reference may be called the Gosse Hypothesis.1
Stars are not distributed evenly throughout our galaxy; instead many, if not most, occur in clusters. These clusters are undoubtedly the result of the original gas clouds being too large for only one or a few stars to be formed. Creationists deny this, of course, and declare instead that God simply created clusters of stars. But this leads to a problem which, to my knowledge, they have not even attempted to resolve. Before we can discuss this problem, however, we need to look at some characteristics of stars.
Distances to stars can be measured without ambiguity, at least when they are close enough to display a measurable parallax. By combining the distance with the apparent luminosity (the observed brightness) we can calculate the absolute luminosity which in turn tells us the rate at which energy, and therefore matter, is being used up by a star. Furthermore, when stars occur in orbiting pairs their masses can be measured. With this data we can calculate the time required for a star to use up all its available matter; i.e., the life-span of the star. Another characteristic of stars which is easily measured is the temperature. This is done by examining its light spectrum; blue stars are the hottest, red stars the coolest.
When a survey is made of the stars for which all these measurements have been made, some interesting facts emerge. When the absolute luminosity of the stars is plotted against temperature (Hertzsprung-Russell diagram), almost all the stars fall along a straight line called the main sequence; the brighter the star the higher its temperature. This is not too surprising. yet it is important because it enables us to distinguish between main sequence stars and other stars, such as red giants and white dwarfs, which fall off the main sequence on the diagram by virtue of their atypical physical size, large or small. More interesting in the context of the present discussion is the finding that the brighter and hotter main-sequence stars also have the greater masses. We conclude that it is in fact the mass of the star, as formed, whether created or evolved, which determines its position on the main sequence.
But now we come to the crucial finding: The hot, bright, blue stars put out so much energy that in spite of their greater initial mass (actually because of it), they will burn themselves out much faster than the cool, faint, red ones.
While the first kind may have life-spans of a few million years, the second kind may live for tens of billions of years-longer, in fact, than the current estimates for the age of the universe. Let me emphasize that this finding is not based on some "fancy evolutionary theory," but is the result of simple calculations based on straightforward measurements of mass and absolute luminosity. It is also important to understand that being able to determine the life-span of a star does not mean that we can look at a star and tell how old it is. We know of course that a blue star must be relatively young since it doesn't live very long. A red main-sequence star, on the other hand, can be practically any age.
We are now ready to consider the clusters. If they were created only about 10,000 years ago we would expect all the main-sequence types to be represented since even the short-lived ones live longer than 10,000 years. Some clusters do in fact have the short-lived stars well represented, indicating that they are less than a few million years old and conceivably only 10,000 years. In the case of most clusters, however, the shorter-lived stars above some point on the main sequence are missing, while the longer-lived ones below are present. The location of this point is different for different clusters. All the clusters have the longest-lived stars represented and never do we find a cluster which has the large blue, shortlived main-sequence stars but not the small red, long-lived ones. Again we are stuck with two alternatives. The first is that. the distribution of main-sequence types in a cluster is a function of its age. The second is, of course, again the Gosse Hypothesis; by never leaving out the long-lived stars, but frequently omitting the short-lived ones, our creator has again deceived astronomers into concluding that the universe has existed for several billion years!
An old argument against the creationist notion that the universe is only 10,000 years old is the following. Given such a short time, how is it that the light from stars and galaxies, millions of light-years distant, has been able to reach us? At one time, creationists were less concerned with appearing as bona fide scientists, and their "simple" explanation was that the creator placed the photons in positions already well on their paths from the sources toward the earth, thus giving the universe the appearance of being much older than it actually is. A straight-forward and rather refreshing admission of adherence to the Gosse Hypothesis!
Today, creationists have a seemingly much more sophisticated way of dealing with this problem.2 The argument is based on a strange article by Moon and Spencer3 which actually appeared in a professional journal. This article has nothing to do with the creation/evolution issue; instead, as was still common in the 1950's, the authors apparently had an obsessive desire to disprove relativity, including the special theory, and the article was written to this end. (As it happens, creationists do in general strongly disapprove of relativity.)
A basic tenet of relativity is that the speed of light is a relativistic invariant; i.e., it is independent of any movement of either the source or the observer. The celebrated Michelson-Morley experiment actually does not exclude the possibility of light being dependent on the movement of the source, and the theory that it is had quite a few adherents for a while. However, on the assumption that this theory was correct, it was expected that certain binary stars would show double images, which in fact they do not. As is almost always possible, Moon and Spencer managed to come up with an "explanation" which would get around this difficulty. They proposed that while material objects exist in Euclidian (flat) space, light travels in Riemannian (curved) space! It is somewhat ironic that Riemannian space with a radius of curvature of billions of light-years, in which everything exists and travels, is used in General Relativity. Perhaps the most sidesplitting assumption in the theory of Moon and Spencer is the size of their radius: 5 light-years. Why 5 light-years? Because this is large enough so that the curvature can not be detected by any experiments performed in the solar system, yet small enough to take care of all the binary stars studied! What we have here is nothing more than a mathematical trick specifically designed to make things appear just the way Moon and Spencer wanted them.
One has to entertain the possibility that the article was written and published as a joke. But creationists certainly don't take it as a joke; to them it must seem like a godsend. With light traveling in a Riemannian space having a radius of only 5 light-years, the time it would take to reach us from any source no matter how distant would never exceed 16 years! Again we see the Gosse Hypothesis in all its glory. The creator decreed that light, and only light, should travel in a Riemannian space with a 5-light-year radius, again for the purpose of making the universe appear to be much older than the actual 10,000 years. As an added bonus, it made us poor fools accept the preposterous notion of relativity!
Although somewhat off the subject, a brief note here will vividly illustrate the sorry state of creationist "science." Slusher still believes (in 1980!) that getting around the evidence of the binary stars would constitute a severe blow against Special Relativity, something he relishes. He apparently doesn't know that the unreliability of this evidence has been recognized at least since the early 1960's, although for a completely different reason.4 He furthermore doesn't know that laboratory experiments utilizing rapidly moving sources have confirmed that the speed of light is independent of the motion of the source,5 thus making the observations of the binaries totally irrelevant.
Distribution of Nuclides6
My final argument is not astronomical but involves physical observations right here on earth, except for one made on the moon. The different atoms constituting the elements and all their isotopes are referred to collectively as the nuclides.
Some of these are stable, the rest are radioactive with half-lives ranging from a small fraction of a second to tens of billions of years. (The half-life is the time it takes for one half of the atoms of a particular kind to decay.)
There are 47 nuclides with half-lives between 1.000 and 50 million years. If the earth were only 10,000 years old, then there should be detectable amounts of all 47 in nature because 10,000 years is not enough time for them to decay totally. However, only 7 of these are actually found, and that is only because they are continually being generated: 4 of them are members of natural decay series; C-14 is generated by cosmic rays acting on nitrogen nuclei; Np-237 is produced by cosmic rays on the moon; and the 7th, U-236, is generated by slow neutron capture in uranium ore where neutrons are available. Creationists have to explain why the other 40 are missing. What makes this significant is that all 17 nuclides with half-lives longer than 50 million years are found in nature.
Simple calculations show that this division between nuclides which are absent and those that are present is exactly what would be expected if all the nuclides were generated (probably in some star) about 4.5 billion years ago. The longest-lived one among the 40 absentees is Sm-146 with a half-life of 50 million years. If it had existed for 4.5 billion years, only 8 x 10-28 of the original amount would remain today, which would explain why it has not been detected. The same would, of course, be true of those with even shorter half-lives.
Among the 17 that are found in nature, the shortest-lived one is Pu-244 with a half-life of 82 million years. In this case, 3 x 10-17 of the original amount would still exist after 4.5 billion years. This, in combination with the fact that it has been found in a concentration of 9 x 10-20, would give an initial concentration of 0.003 or 0.3% in this particular ore which is quite reasonable.
For the situation of the earth being only 10,000 years old, we can calculate the probability of the 40 short-lived ones being absent and the 17 long-lived ones being present, as opposed to some random distribution between absence and presence which would then be possible; namely 40!17!/57! = 7 x 10-15. (An exclamation mark indicates the factorial.) Actually, if we are assuming that the distribution is accidental, we should really add the approximately 260 stable nuclides to the 17 long-lived ones since they are all found, giving a probability of 6 x 10-52. In either case, creationists are surely not about to claim that the distribution is accidental. This leaves them, at the risk of seeming repetitious, with only the Gosse Hypothesis!