|Landscape in Carina Nebula [Courtesy NASA]|
In one respect, the "cafeteria" approach is entirely reasonable, since some scientific theories are much more firmly established than others. For example, there is considerable debate among the scientific community at the present time over the question of whether the observable universe is merely one island in a vast (or even infinite) sea of universes, collectively known as the "multiverse." Brian Greene, in his popular 2011 book The Hidden Reality, discusses the various multiverse theories and then urges his readers to recognize that ultimate reality might be much broader and more exotic than we have heretofore imagined: "It's only through the rational pursuit of theories, even those that whisk us into strange and unfamiliar domains, that we stand a chance of revealing the expanse of reality." [Greene2011, pg. 322]. On the other hand, in a August 2011 feature article in Scientific American, George Ellis addresses several multiverse proposals, and then concludes "All in all, the case for the multiverse is inconclusive. The basic reason is the extreme flexibility of the proposal: it is more a concept than a well-defined theory." [Ellis2011].
Even in the arena of biological evolution, there are certain issues at the frontiers of research that represent genuine issues of debate at the present time. One example of public scientific controversy is Homo floresiensis, the remarkable hominin fossil more commonly known as the "hobbit" due to its diminutive size, which remarkably co-existed with humans until as recently as 17,000 years ago [Wade2004]. The discoverers pointed out that the fossil combined an unusual mix of human and early hominid features, including a nearly complete skull that most resembled Homo erectus, but with legs more akin to Australopithecines. But other researchers disagree. Biologists Maciej Hennenberg and Alan Thorne dismissed the notion of a separate species, saying that the small skull instead represented merely a case of microcephaly, a malady that causes dwarfism in afflicted humans. In response, Brown and Morwood acerbically described Henneberg and Thorne's article as "an extremely poorly informed, and ill designed, piece of 'research'." The consensus of peer-reviewed studies seems to be shifting to support the original hypothesis, namely that the Flores skeletons represent a related but distinct hominin species [NS2010]. However, one would be well within reasonable bounds to be skeptical of the entire notion.
But other theories, more basic to the core of modern science, are not so easily dismissed. In particular, the basic notion that the earth is many millions of years old is extremely well established at the present time. These dates, and the underlying radiometric schemes they are based on, have been scrutinized in many thousands of peer-reviewed papers for at least 50 years, and are widely regarded as highly reliable, although still subject to occasional minor errors of various sorts (see Ages and Reliability). Almost as well established is the fact that species on earth today are descended from one or a few original species over the eons, and that the chief forces in this evolution have been mutation and natural selection. This central tenet of evolutionary theory has been tested exhaustively in many thousands of peer-reviewed papers (e.g., in recent DNA studies), and is not presently considered to be in serious doubt in the scientific community (see DNA and Evolution).
One of present author's favorite activities is hiking in the many lovely mountains and hills of northern California. At the present time, many hikers in this area (and elsewhere worldwide) engage in "geocaching" in conjunction with their hikes. This consists of using an inexpensive Global Positioning System (GPS) receiver to find some of the more than one million "geocaches," namely small containers with log sheets and, in some cases, valuable items such as hiking supplies, which are hidden at spots whose latitude-longitude coordinates are provided at the Geocaching website. Geocaching with a GPS receiver makes hiking more interesting, but also provides valuable protection against getting lost or disoriented in the hills. In a similar way, the many automotive GPS receivers now in use are an invaluable resource for those who frequently drive on unfamiliar streets or highways, ensuring that they will not become "lost" after a wrong turn (if used properly).
It is a fact that every time a hiker heads out to find a geocache in the hills, and every time a driver consults his or her GPS mapping device, he or she threatens to overturn the foundations of modern science. This is because the GPS system is a symphony of modern science and technology, and if any "instrument" of the symphony were faulty, the entire system might well collapse. Furthermore, if some fundamental physical law underlying GPS technology were found to be faulty, much of the rest of modern science would also be drawn into question, including, for instance, geology and evolutionary biology. One key body of evidence in geology and evolution are the radiometric dates of various rock layers, which are based on measurements of trace amounts of certain radioactive isotopes in rock minerals. A key assumption in these measurements is that radioactivity is correctly described by certain key principles of quantum mechanics, and that these principles do not change measurably over time, nor are they affected by temperature, pressure, magnetism or chemical combination. In a similar way, modern big bang cosmology is based in part on general relativity, and the calculated age of the universe had better not be less than the age of rocks on the earth, or else we have a major problem! Thus any scientific experiments or measurements that threaten the integrity of either quantum physics or general relativity pose a grave challenge to both modern geology and evolutionary biology.
Along this line, consider:
In similar way, numerous experiments have been performed to see whether rates of radioactive decay change with heat, pressure or magnetic fields, but no variation has been noted for any of the isotopes used in geologic dating [Dalrymple2004, pg. 58-60]. Also, the spectral lines of light rays reaching the earth from distant stars, generated by atomic processes that occurred millions (or even billions) of years ago, exhibit the same frequency patterns that are predicted by the laws of quantum physics as we understand them today, and which we see confirmed in modern-day experiments [Barrow2007, pg. 124-128]. Again, no significant deviation from theory has been detected to date, even in highly exacting experiments. So these theories must be taken seriously.
If nothing else, the cafeteria approach is intellectually inconsistent -- if one really believes that much of modern geology and biology should be rejected because radiometric dating (and thus quantum theory), for instance, is not reliable, then one should avoid using any smartphone with GPS mapping capabilities, since, as we have seen, at some level they are designed on the same physical principles as radiometric dating. In fact, one should distrust and avoid a wide range of computers and high-tech gadgets, since virtually all of these critically rely on electronic designs based in quantum mechanics. Along this same line, if one does not accept evolution, one should also distrust and avoid numerous medical procedures and medications, such as the very frequently prescribed directive to use an antibiotic through its full course, so that the targeted antigens do not develop resistance to the drug.
The list goes on and on -- the cafeteria approach is not only ineffective in bringing harmony to science and religion, it is also ineffective in daily life. This does not mean that we should accept anything that emanates from the world of modern science without question -- countless genuine controversies are discussed in peer-reviewed literature every day -- but it does mean that blanket and unthinking rejection of well-established scientific results, simply because we might not like the conclusions, is not a productive way to proceed.
For additional details, see Theory.