Young Earth Creationism, Part IV

(January 19, 2018)

This is the final part of our series on Young Earth Creationism (YEC). In the preceding three parts, we reviewed our current scientific understanding of the origin and evolution of the Universe. Scientists have obtained an enormous amount of data, all of which is consistent with the interpretation that our current Universe began as an exceptionally hot and dense plasma some 13.8 billion years ago. This plasma has been expanding and cooling since that time. Our solar system and Earth formed some 4.5 billion years ago.

In contrast, Young Earth Creationists claim, based on a literal reading of the Judeo-Christian Bible, that the Universe and solar system are the same age, roughly 6,000 years old. Moreover, they insist that an objective assessment of the evidence leads one to this conclusion. In this series we have reviewed in some detail the existing evidence and conclusions that are drawn from the data. We demonstrate that all evidence regarding the age of the Universe and the solar system is consistent with the conclusions drawn by scientists.

In addition, in Part III of this series we reviewed the pseudo-scientific “theories” advanced by Young Earth Creationists (YEC). We showed that they require ignoring or misrepresenting vast amounts of existing data. YEC “theories” are justified, at best, by very small amounts of cherry-picked and sometimes doctored scientific data, and they ignore contradictions with the preponderance of experimental evidence. Finally, several of the YEC models are mutually contradictory.

The YEC models can only be supported by the following logic. First, one assumes that assertions in the Bible represent inerrant fact, that e.g., references to the Six Days of Creation refer to literal 24-hour days, and that claims of exceptionally long human lifetimes (~ 1,000 years) in Biblical accounts are correct. One then introduces drastic, “miraculous” temporary changes in the laws of nature and physical constants, in order to obtain agreement with Biblical accounts.

We point out that YEC scenarios represent the very opposite of credible scientific theories. In part III of this series, we reviewed several models that have been concocted by YEC partisans. We show that in all cases the models fail to achieve scientific respectability or relevance.

In section 5 of this last part, we review YEC claims that the Big Bang Scenario, the existing scientific framework for the evolution of the Universe, is fatally flawed. We show that such claims are without merit. Then in section 6 we point out that the YEC “theories” are unfalsifiable. In addition to all of their other faults, these YEC models fail to meet an essential criterion for a legitimate scientific model.

5.  Debunking Creationist Pseudoscience II: False Claims of Flaws in Big Bang Cosmology

Having failed to produce any coherent or even mildly convincing alternative scientific explanation for the vast database of observations of our Universe, young Earth creationists have invested great energy into attempts to discredit Big Bang cosmology and reduce it to the status of a competing religion. The Big Bang Scenario (BBS) has undergone considerable refinement over the past two decades, in response to enormous quantities of new observational data of unprecedented precision. We anticipate further refinements to the BBS as future data are obtained. As is the case for nearly all scientific theories, the Big Bang Scenario contains a small number of adjustable parameters whose values are determined empirically, and are not yet predicted from a more fundamental theory. Dark matter and dark energy densities are two examples of these parameters. Experimental tests of some Big Bang predictions are ongoing. An understanding of the initial conditions from which the expansion of our Universe began is really beyond the scope of Big Bang cosmology; this has motivated the introduction of currently speculative models of a multiverse undergoing “eternal inflation.”

These ongoing efforts are all part of applying the standard scientific method to a field where the available instrumental techniques are getting rapidly more sophisticated. When we consider open questions for this theory, it is important to recognize that they have limited impact on the inferred age of the Universe, which is by now a robust scientific result. As we will show in this section, young Earth creationists use arguments debunked below to argue (incorrectly) that the present incompleteness in Big Bang cosmology renders irrelevant the whole of our hard-won understanding of the Universe.

5.1  Discounting Successful Predictions

Many young Earth creationists have seized upon a somewhat obscure debate within the scientific community concerning the best model to account for the central experimental cosmological parameters. These include the ongoing expansion of the Universe, the existence, temperature and fluctuations of the Cosmic Microwave Background (CMB) and the synthesis of the lightest nuclei. Proponents of a steady-state model for the Universe have formulated a “cosmology statement” emphasizing the still mysterious features of Big Bang cosmology. They therefore argue that some funding should be diverted from ongoing tests of aspects of the Big Bang Scenario (BBS), to support further development of competing models. Such arguments have very limited support from the scientific community, because the proposed scientific alternatives to the BBS involve more contrived explanations for the observational data. But the statement contains the following sentences that have been widely quoted in the young Earth creationist community:

What is more, the big bang theory can boast of no quantitative predictions that have subsequently been validated by observation. The successes claimed by the theory’s supporters consist of its ability to retrospectively fit observations with a steadily increasing array of adjustable parameters, just as the old Earth-centered cosmology of Ptolemy needed layer upon layer of epicycles.”

Young Earth creationists do not bother to quote other parts of the cosmology statement. For example, that statement points out that without dark energy, the standard BBS model would predict a Universe only 8 billion years old – a value still enormously at odds with the answer assumed by young Earth creationists. The cosmology statement, by the way, does not mention that without dark energy, cosmology would be unable to account for the observed and confirmed acceleration of the Universe’s expansion. We do not yet understand the source of dark energy, but the need for it is clearly established.

But is the cosmology statement correct, that the Big Bang Scenario lacks successful quantitative predictions? That claim relies on questionable technicalities and/or willful neglect to discount the clear predictions from the BBS. The greatest success of Big Bang cosmology – the one that effectively killed steady-state cosmology alternatives – was the 1948 prediction by Ralph Alpher and Robert Herman that there should be a pretty uniform relic background radiation pervading the Universe, and that this radiation should exhibit the thermal spectrum of a blackbody at a temperature about 5 degrees above absolute zero. This predicted CMB radiation should have been left over from the cosmological epoch when electrons and nuclei combined to form stable neutral atoms, after which photons subsequently stopped interacting frequently and intensely with electrically charged particles. The maintenance of a blackbody form for the emission spectrum over cosmological time is a highly non-trivial prediction that relies on the ongoing expansion of cosmic space, as we explained in Sec. 4.1 of this blog series.

Young Earth creationists, along with promoters of alternative cosmology models, discount the success of the CMB prediction by arbitrarily moving its experimental discovery backward in time from the widely accepted date of 1964 (as summarized in Sec. 3.5, which led to the 1978 Nobel Prize in Physics for Arno Penzias and Robert Wilson for their groundbreaking radio-astronomy measurements) to about 1941. This exercise in revisionist history characterized Alpher and Herman’s work as a “post-diction” rather than a prediction. What happened in 1941 was the interpretation of optical astronomy measurements that had been made by Adams and Dunham in the late 1930’s. They had observed dark lines in their spectra corresponding to the absorption of light by interstellar molecules including carbon nitride (CN). But light was absorbed not only by the CN molecule in its lowest energy state, but also in a low-lying excited rotational state. In 1941 McKellar showed that the inferred relative population of the ground and rotational states of interstellar CN molecules corresponded to a thermal distribution at a molecular temperature 2.3 degrees above absolute zero.

However, this 1941 observation played no role in the CMB prediction by Alpher and Herman, nor in the subsequent interpretation of Penzias and Wilson’s radio-astronomy measurements. If it had played a role and Big Bang theorists were only “retrospectively fitting observations,” why didn’t Alpher and Herman adjust their assumptions to post-dict a temperature of 2.3, rather than 5 degrees? Indeed, it was recognized only after the 1964 discovery that this 1941 result had anything to do with CMB radiation – we now understand that the CMB radiation excited the CN molecules, and that both the radiation and the interstellar CN were in thermal equilibrium.

The 1964 interpretation of the observations by Penzias and Wilson demonstrated that the actual temperature of the CMB was about 2.7 degrees above absolute zero. In the 1990’s, the Cosmic Background Explorer (COBE) spectacularly confirmed that the CMB radiation was quantitatively consistent with a blackbody spectrum – see, e.g., Fig. 3.7. Alpher and Herman’s prediction for the temperature of the CMB blackbody spectrum was incorrect because in 1948 there was far less reliable data than today to constrain the details of the Universe’s expansion timeline.

Young Earth creationists have also pressed allegations of conspiratorial mis-dating of discoveries and model proposals. All of these represent YEC attempts to label Big Bang theory as forcing an ex post facto fit to well-established observational data. This point is belabored on the misleadingly named Real Science Radio site, which lists alleged failures of the BBS. These young Earth creationists appear not to recognize that scientific theories seldom emerge as full-fledged “bolts from the blue.” Rather, new models build on earlier theoretical ideas and evolve as they attempt to explain observations that are not yet understood.

Consider the origin and history of the Hubble Constant. The astronomer Vesto Slipher indeed measured the recession velocities of some galaxies in the first two decades of the 20th century, prior to Edwin Hubble’s work. But it was Hubble in 1929 who first published the observational result that recession velocities appeared to be proportional to the distance of galaxies from Earth (see Fig. 3.2) – i.e., the so-called Hubble’s Law. Einstein had published his equations of General Relativity in 1916, and Alexander Friedmann had interpreted them in 1922 under the simplifying assumptions of a Universe that was homogeneous and isotropic on large scales. Friedmann’s equations clearly allow for solutions in which space expands over cosmological time. And Georges Lemaȋtre showed in 1927, prior to Hubble’s publication, that a specific general-relativistic solution for an expanding Universe of constant mass could account, in principle, for the recession velocities observed by Slipher. This would lead to the proportionality between recession velocity and distance subsequently established from observations by Hubble.

Young Earth creationists quibble over who “discovered” the Universe’s expansion, who “discovered” Hubble’s Law, who developed the Big Bang treatment, and at what precise date each accomplishment was achieved. But individual attributions and the timeline of events are irrelevant to the question of whether Big Bang cosmology provides an accurate picture of the age of the Universe. Allowance for an expanding cosmos is built into Einstein’s theory of General Relativity. The seeds of Big Bang theory were certainly embedded in Lemaȋtre’s work, but the implications were much further advanced in the 1940’s by the work of George Gamow, Ralph Alpher and Robert Herman. The discovery of the CMB stimulated dramatic progress in the Big Bang Scenario and its implications in the 1960’s. In recent decades, Big Bang cosmology has continued to develop, as scientists have gained orders of magnitude more data relevant to the sources of energy in our Universe. The rapid development of precise experimental tools has stimulated corresponding advances in theoretical cosmology – and that is precisely the way the scientific method is supposed to work.

The discounting of Big Bang predictions furthermore ignores the very important successes of Big Bang nucleosynthesis, research first undertaken in the 1940’s by Ralph Alpher, working on his Ph.D. thesis under the supervision of George Gamow. The expansion and temperature history of the Universe, as interpreted within Big Bang cosmology, combined with nuclear reaction rates for light nuclei measured in the laboratory, predict that the Universe should contain roughly 25% as much mass in helium atoms as in hydrogen atoms (see Sec. 3.4). This value is in excellent agreement with measured astronomical abundances.

BBN baryon to photon ratio
Figure 5.1. Relative primordial abundances of the light nuclei deuterium (D), helium-4 (4He), helium-3 (3He) and lithium-7 (7Li), relative to hydrogen (H), as predicted (solid colored curves) by Big Bang nucleosynthesis, as a function of the ratio of baryon-to-photon densities. Yellow boxes indicate the range of abundances observed from astronomical sources. The cross-hatched vertical bands indicate the value and uncertainty in that ratio determined from independent Big Bang fits to astronomical abundances (red cross-hatching) or CMB features (blue cross-hatching). The figure is reproduced from http://pdg.lbl.gov/2015/reviews/rpp2015-rev-bbang-nucleosynthesis.pdf .

As seen in Fig. 5.1, the helium-4 fraction is not terribly sensitive to the one adjustable parameter on which Big Bang nucleosynthesis calculations rely, namely, the ratio of photon-to-neutron and proton (i.e., baryon) densities at the start of the nucleosynthesis period a few seconds after the Big Bang. However, the abundance of deuterium atoms is very sensitive to that ratio, and determines its value when Big Bang nucleosynthesis calculations are adjusted to explain astronomical deuterium abundance observations. The same ratio was much later determined completely independently, and even more precisely, within Big Bang cosmology fits to the observed power spectrum of CMB radiation (see Fig. 3.9).

Big Bang skeptics invariably point out that the photon-to-baryon ratio is a number fitted to observations, rather than predicted. Also, they correctly note that astronomical abundances of lithium are still not quantitatively understood within Big Bang nucleosynthesis. But they ignore the critical fact that the two independent determinations of the photon-to-baryon ratio from atomic abundances and CMB features, each relying on Big Bang cosmology, are in complete agreement with one another, as emphasized in Fig. 5.1. That agreement is, indeed, another powerful quantitative prediction of Big Bang cosmology.

The quantitative consistency of Big Bang cosmology with a wide variety of observations, some of which were described in Sec. 3, is a major success of the theory. The number of data points accounted for, as typified by Fig. 3.9, exceeds the number of adjustable parameters by orders of magnitude, and that is the measure of a successful theory. Despite the serious open questions in our current understanding of some features of cosmology, Big Bang theory is the only successful explanation of what we already know. To quote astrophysicist Ethan Siegel from his recent book Beyond the Galaxy:

To this very day, there is no other model that is both consistent with General Relativity and explains the Hubble expansion of the Universe, the abundances of the light elements and the existence and properties of the cosmic microwave background; the Big Bang is the only one.”

5.2  Confusing Parameters of a Theory with its Predictions

Nearly all scientific theories and models with which one can make quantitative calculations include parameters whose values must be adjusted to fit some experimental data. While scientists hold out hope for eventual “theories of everything” that will provide first-principles accounts of these adjustable parameter values, no successful theories of everything have yet emerged. So long as theories with adjustable parameters are able to account successfully for far more data than are needed to fix the parameter values, the theories provide useful accounts for what we observe in nature. In fitting observations, one tries to use as few adjustable parameters as possible. But as new, more precise, data become available, it often becomes necessary to use additional parameters to provide an updated account.

As an example, the Standard Model of particle physics contains some twenty-odd parameters, such as fundamental particle masses and interaction strengths. These values are not predicted a priori, but are determined empirically. Once those parameter values are fixed, the Standard Model accounts for nearly all observations yet made of particle behavior and interactions. The Standard Model still has important open questions, some of which will be dealt with below. As a result, physicists believe the Standard Model is only a very good approximation to a more fundamental theory that may eventually be discovered. But in the meantime, Standard Model predictions for a wide variety of phenomena provide an excellent reproduction of nature.

Initially, neutrino masses were set to zero in the Standard Model, because non-zero masses were unnecessary to account for experimental results. However, more precise experiments over the past two decades have shown that neutrinos clearly have non-zero, though very small, masses. This empirical fact required tweaks to the original version of the Standard Model. The failure to predict beforehand that non-zero neutrino masses would be necessary does not overthrow the Standard Model, or render it useless or irrelevant; it simply requires additional parameters to account for the new, more precise data.  The predictive power of the theory is still extensive and impressive.

In contrast to this scientific understanding of the way scientific theories evolve, young Earth creationists argue for the complete rejection of Big Bang cosmology because it did not predict beforehand the need for some newly emphasized parameters. For example, they argue that the failure to predict the need for dark energy beforehand is a fundamental flaw of Big Bang cosmology. Dark energy is treated in current analyses by the cosmological constant that has been included in Einstein’s General Relativity theory since 1917. But before 1998, there was no astronomical evidence that required non-zero values of this constant to be considered. The more recent conclusive experimental evidence that the expansion of cosmic space is accelerating now absolutely requires a non-zero value of the cosmological constant; consequently, that parameter has been adjusted to fit the new data. Inclusion of that additional parameter improves the quality of reproduction of cosmological data and, hence, the reliability of other extracted values, such as the age of the Universe.

Admittedly, we currently have no theoretical understanding of the value extracted for the cosmological constant, nor do we have data that yet requires the introduction of parameters beyond the cosmological constant to account for the history of expansion rates in the Universe. Just as in the case of the Standard Model, these shortcomings encourage our ongoing search for more fundamental theories. However, this does not mean that our current understanding of Big Bang cosmology is untrustworthy.

In a similar vein, young Earth creationists question the usefulness of Big Bang cosmology because it did not predict the existence of dark matter. The need to consider dark matter was indicated by observational results that have nothing to do with Big Bang cosmology. The first data that suggested contributions from dark matter were orbit velocity measurements for stars and hydrogen atoms far out from the centers of galaxies. Additional support for dark matter came from astronomical mass distributions inferred from gravitational lensing observations.

Within Big Bang cosmology, the history of the expansion of the Universe, and hence the extraction of the age of the Universe, rely primarily on the balance between the overall (visible plus dark) matter, radiation and dark energy densities in the Universe (e.g, on the baryon-to-photon density ratio considered in Sec. 5.1). Dark and visible matter exert the same gravitational forces, so that the distinction between them enters into analyses primarily via their anticipated velocity differences in the early Universe. The most frequently adopted assumption of cold dark matter (see Sec. 3.7) assigns it much lower early-Universe velocities than those for matter composed of known baryons. As a result, dark matter provides more effective early attractor sites for the formation of galaxies and galaxy clusters. This difference strongly affects fits to the peaks in the CMB power spectrum of Fig. 3.9 because the propagation of early universe sound waves is sensitive to it; but it has little effect on the extracted age of the Universe.

As with dark energy, we do not yet understand the microscopic source of dark matter; but many experiments are under way to search for that source, so we may get an answer within the next decade. Still, the inclusion of dark matter is essential to explain a number of observed astronomical features, and it provides a more robust Big Bang account for all of the cosmological observations. Thus, the assumption of both dark matter and dark energy provides us with a more (not less) reliable extracted value for the age of the Universe.

The Real Science Radio site furthermore claims erroneously that Big Bang cosmology predicts an entire Universe of antimatter that has not been discovered. This claim belies a misunderstanding of contemporary particle physics research. One expects the initial conversion of energy to mass in the Big Bang to have produced matter and antimatter in equal amounts. But subsequently the matter and antimatter would have annihilated each other, converting all mass to radiation energy in the early Universe, unless there were differences in the interactions and decays of matter vs. antimatter particles.

The value of the baryon-to-photon ratio extracted from Big Bang nucleosynthesis and CMB analyses tells us that the required differences are tiny, on the order of one part per billion. Andrei Sakharov outlined in 1967 the physics conditions that would have had to exist in the early Universe to allow for such differences, involving tiny deviations from some physics conservation laws. Deviations have been observed in laboratory experiments, but not yet at the level needed to account for the part-per-billion inferred differences in the early treatment of matter vs. antimatter. Credible theoretical speculations have been advanced for how these differences might have arisen, but physicists continue searching for experimental verification of such speculations. The source of this matter-antimatter imbalance is an ongoing challenge for particle physics, but not for Big Bang cosmology per se.

Young Earth creationists further fault Big Bang cosmology for not predicting cosmic inflation, even as they simultaneously contend that cosmic inflation is a hoax. An inflationary early period of extremely rapid cosmic expansion is a still speculative aspect that has been added on to standard cosmology since 1980. Inflation provides a mechanism to explain the extreme flatness of cosmic space and the temperature uniformity of the CMB inferred from observations, while also yielding tiny primordial quantum fluctuations that could have seeded today’s large-scale structure in the Universe. To date we have circumstantial evidence that favors cosmic inflation, but not definitive confirmation. Inclusion of inflation is not essential to deduce the age of the Universe from fits to supernova, CMB, gravitational lensing, and baryon acoustic oscillation data. If we fail to find more robust experimental evidence in favor of cosmic inflation, this will leave the first 10-32 seconds of universe evolution open to question, but it will have little impact on cosmologists’ account of the expansion history and timeline of the Universe over the past 13.8 billion years.

None of the alleged “failed Big Bang predictions” touted by young Earth creationists can alter the scientific view of cosmology enough to account for the observed Hubble expansion of distant galaxies, and for measured CMB distributions with an age of the Universe within even six orders of magnitude of the literal biblical account. Rejecting Big Bang cosmology because the original version did not predict the existence of dark energy or dark matter is analogous to declaring Newton’s Laws of motion useless, because Newton did not anticipate the eventual need for relativistic corrections to our understanding of motion near light speed. As science advances successful theories are amended, or they are subsumed in more fundamental theories that incorporate the successful predictions of the earlier ones.

5.3  Misinterpreting Inconclusive Experiments as Conclusive Evidence Against a Theory

Science deniers are fond of magnifying small technical challenges for a theory, particularly ones that do not even test fundamental tenets of the theory, into “nails in the coffin” of the theory. They seize on inconclusive or occasionally incorrect experimental results to make their argument. Young Earth creationists also make use of this standard element of the science denier’s toolbox. We offer two examples highlighted on the Real Science Radio young Earth creationist website.

In an attempt to demonstrate that the CMB is not primordial radiation last scattered billions of years ago, but rather comprises electromagnetic waves from a nearer source, creationists overemphasize what they label as “the missing CMB shadow of the Big Bang.” The “shadow” referred to here is the so-called Sunyaev-Zel’dovich effect (SZ effect), whereby CMB photons originating beyond a galaxy cluster may scatter on their path toward Earth from energetic ionized electrons in moving cluster gas. Such scattering is predicted to induce a tiny shift in frequency from the pure CMB blackbody spectrum. A 2006 analysis (R. Lieu, et al., The Astrophysical Journal 648, 176 (2006)) of CMB data from the WMAP survey concluded that those data did not yet definitively demonstrate the anticipated small amplitude SZ effect, but rather placed upper limits on its size. On that basis, Real Science Radio continues to proclaim that “the missing shadow is yet another failure, not of an incidental off-the-cuff prediction but of a fundamental requirement of the big bang.” Their reports of Big Bang’s “death” were somewhat premature, as the SZ effect has by now been observed definitively in data analyses for a number of massive galaxy clusters, for example, in this work  based on observations with the Atacama Large Millimeter/submillimeter Array. Additional observational searches for SZ evidence are ongoing.

Additional premature “coffin nails” were claimed by creationists in 2014, when preliminary reports of the detection of a “smoking gun” for cosmic inflation were retracted after a few months. The original claim by the BICEP2 collaboration was based on observation of certain telltale patterns in the polarization (i.e., preferential electric field orientation) of CMB radiation, patterns predicted to arise from the imprint of gravitational waves emitted during the period of cosmic inflation proposed as the origin of the Big Bang. Subsequent data and analyses showed that the patterns observed by BICEP2 could have arisen, at least in significant part, from effects of interstellar dust that had been underestimated in the original BICEP2 analysis. The normal processes of self-correction embedded in the scientific method had, in a matter of months, reduced what first appeared to be a major discovery to simple upper limits on the amplitude of the predicted primordial gravitational waves. Many second-generation telescopes are now beginning to acquire much more extensive data on the CMB polarization in continuing searches for the inflationary gravitational wave imprint.

But Real Science Radio hastens to report that “the gravity wave hysteria also illustrates the lack of predictive value of what is essentially a speculation on top of a speculation, that is, the inflation period of the big bang. Also exposed was the extreme viewpoint bias and gullibility of the scientific community, of the secular media, and of the old earth progressive creationists…” They fail to emphasize that it was the scientific community that corrected the initial excitement, or that Big Bang dating of the Universe, which is not speculative, would not change dramatically if the speculative proposal of cosmic inflation turns out not to be valid. Once more, young Earth creationists would be well advised to hold onto their coffin nails until we obtain more and better data on CMB polarization that will emerge within the coming decade.

Interestingly, Real Science Radio lauds as “great science” the subsequent 2015-16 discoveries by the Laser Interferometry Gravitational Wave Observatory (LIGO) of gravitational waves generated by the merger of distant orbiting black holes. (Equally exciting was the 2017 detection of gravitational waves from merging neutron stars.) That was indeed great science, and it resulted in the 2017 Nobel Prize in Physics being awarded to Barry Barish, Kip Thorne and Rainer Weiss of LIGO. Real Science Radio stresses that “unlike the case of gravity waves from an alleged inflationary period, these amazing detections of gravity waves from black hole mergers do not provide evidence in support for either the inflation period, nor for the big bang itself.” That statement is correct. But it does manage to hide the fact that the detection of those gravitational waves confirmed a prediction of Einstein’s General Relativity, according to which those waves travel through space at the constant speed of light. The first detected waves were in transit toward Earth at that speed for some 1.3 billion years from the distant merging black holes that generated them. Furthermore, analyses of the gravitational wave data provide independent confirmation (see Table 3.2) for the Hubble constant values (hence, for the age of the Universe) determined from the CMB and from recession speed measurements for distant supernovae. So the “great science” hailed by Real Science Radio is impossible to reconcile with the young Earth creationists’ preferred age of the Universe.

6.  The Unfalsifiability of Creationism

There are still many details about the origins and initial conditions of our Universe that are not yet understood scientifically. There is healthy debate within the scientific community concerning the ultimate falsifiability of the cosmic inflation concept, and even more so, of ideas about a multiverse. Inflationary models predict the occurrence of primordial gravitational waves, but are not capable of predicting their quantitative amplitude. A conceivable future successful observation of the imprint of inflation on CMB polarization could provide confirmation of the primordial gravitational waves, but a failure to observe that imprint may not provide conclusive evidence that they don’t exist.

Most inflationary models lead naturally to eternal inflation, in which new baby Universes are continually bubbling out of inflating space-time in a multiverse, but there are not yet compelling observational signatures predicted as a signal of the existence of such other Universes. The multiverse is a natural outcome in string theory, but there is to date a paucity of quantitative testable predictions to confirm or refute string theory itself.  Currently there is considerable skepticism about whether these aspects of theoretical cosmology are definitively testable; hence these aspects of cosmology should be regarded as provisional.

In contrast, many aspects of the Big Bang Scenario are either firmly established, or are currently being subjected to critical experimental testing. This includes the particle physics, nuclear physics, General Relativity and cosmology that underlie the Big Bang theory. Thus, the Hubble expansion of the Universe, the cosmic microwave background radiation, and the origin of the light elements are all experimentally validated and well understood. The age of the Universe extracted from these analyses is robust at the level of the few percent remaining discrepancies in the inferred values of the Hubble constant, as summarized in Fig. 3.10. Similarly, the nuclear physics and geology that underlie the radiometric, stratigraphic and fossil dating of the Earth are well established fields of science that provide coherent explanations for a wide variety of observations. The biblical age insisted upon by young Earth creationists is utterly inconsistent with this scientific evidence.

All scientific estimates of the age of the Universe and of the Earth lead to results on the order of 13.8 billion years for the Universe and 4.5 billion years for the Earth. Young Earth creationists resort to drastic methods to “prove” an age on the order of 6,000 years. Their motivation is clear: they begin with a conviction that the Bible is inerrant, and they rely on a literal reading of that book to obtain dates for creation. The young Earth creationists are then forced to invoke supernatural intervention that provides temporary drastic modifications to the known laws of nature.

It should be clear that young Earth creation “science” is, by definition, unfalsifiable. There are no experiments or results that would convince these fundamentalists that their theory was incorrect. Their pseudo-scientific “explanations” rely on miraculous supernatural interventions that cannot be predicted beforehand or subsequently subjected to experimental tests.  Some creationists will admit that their theories cannot be falsified, and it follows that those models cannot be considered as legitimate scientific inquiry. Attempts to sell supernatural pseudoscience as “creation science” range from misguided to fraudulent, and do not advance the religions they purport to defend.