Common Big Bang Cosmology Misconceptions

This attitude began to change dramatically a century ago with publication of Einstein’s theory of general relativity and Hubble’s discovery of the expansion of the universe. George LeMaitre quickly saw that those two developments might imply the universe was neither eternal nor infinite. However, it always is difficult to get out of the rut one is in, so widespread belief in a noneternal and possibly finite universe awaited the discovery of the cosmic microwave background in 1965. Since then, the big bang model, the belief that the universe suddenly appeared in a small, hot, expanding state 13.8 billion years ago has dominated cosmology.

After the general acceptance of the big bang model a half century ago, some Christian apologists began to see the big bang in the Bible.

After the general acceptance of the big bang model a half century ago, some Christian apologists began to see the big bang in the Bible. Their reasoning was that since science has proved that the universe had a beginning, then there must be a Creator, and that Creator is the God of the Bible. However, at Answers in Genesis we have long recognized the incompatibility of the big bang with the creation account of Genesis 1. Therefore, we understand that the big bang model is just one of the many failed attempts of men to rationalize the existence of the world apart from God. Consequently, opposition to the big bang model has been the position of not only Answers in Genesis but also of other biblically based creation and apologetic ministries.

Unfortunately, several misconceptions about cosmology have crept into the thinking of biblical creationists. Here I will discuss some of these misconceptions.

How Can an Explosion Give Rise to the Universe?

This false impression stems from the very poorly chosen name for the standard cosmology, the big bang. That name implies an explosion, which would seem to be a chaotic, jumbled affair, from which no order could arise. However, that isn’t what the big bang model is at all. The “bang” part of the name comes from the sudden appearance of space, time, matter, and energy that the big bang is supposed to be. The big bang was not a hypothetical explosion. Therefore, to ask how order can arise from an explosion is to commit the informal fallacy of equivocation.

Is the Universe Expanding?

There is some misunderstanding about the expansion of the universe, the foundation of modern cosmology. Did Edwin Hubble discover that the universe is expanding? Not exactly. What Hubble found in 1929 was that there is a linear relationship between the redshifts and distances of galaxies. What is redshift? The spectra of galaxies contain absorption lines from their constituent stars. These absorption lines are due to elements in the atmospheres of the stars absorbing energy at specific wavelengths. If the distance of a galaxy is increasing (such as when moving away from us), then the wavelengths of those spectral lines will be shifted to longer wavelengths than they are measured to be in a stationary laboratory. Since longer wavelengths are toward the red end of the visual spectrum, we say that the spectral lines are redshifted. Conversely, if a galaxy’s distance is decreasing (such as moving toward us), then the spectral lines are blueshifted. Hubble measured the distances of a few galaxies, along with their redshifts to show the linear relationship. Hubble’s work was crude by today’s standards, but in the century since, his relationship has been greatly improved upon. What does this linear relationship mean? The most straightforward interpretation is that it indicates the universe is expanding, that is, galaxies are getting farther apart. Keep in mind that this is an interpretation of the data. There could be other interpretations, but until any other good interpretation comes along, this interpretation remains the best. For purposes of discussion, I will assume that this is the correct interpretation. If galaxy redshifts obey the Hubble relation, then redshifts reflect distances of those galaxies, and we say the galaxy redshifts are cosmological.

Hubble knew exactly what he was looking for, because he was aware of one of the implications of Einstein’s theory of general relativity when applied to the universe.

It is worth pointing out that many textbooks imply that Hubble stumbled upon his discovery, but this isn’t the case. Hubble knew exactly what he was looking for, because he was aware of one of the implications of Einstein’s theory of general relativity when applied to the universe. A few years after Einstein published his theory, the Russian mathematician Alexander Friedmann showed that in the general case the universe must either be expanding or contracting. Hubble also was aware of the work of American astronomer Vesto Slipher about 15 years earlier who showed that most galaxies had redshift. Hubble was not the only person who put these two clues together and realized what could be shown astronomically, but Hubble perhaps was the only person who realized this who also had access to the telescopes capable of doing this work.

Are Redshifts Due to Velocity?

A common misconception (not just among biblical creationists) is that universal expansion is due to velocity. That is, many people think that redshifts of galaxies are due to galaxies moving away from us. Thus, the redshifts of galaxies are compared to the Doppler effect, where the wavelength of any wave phenomenon (such as sound) that is emitted by an object moving away from the observer is shifted to longer wavelengths. However, in general relativity the proper understanding is that it is space that is expanding. As space expands, it carries galaxies along with it. Galaxies move with respect to space, but even if they weren’t moving, they still would recede from us as space expands. This distinction between cosmic expansion and the Doppler effect may sound like a very fine point, but it is important. For instance, cosmic inflation is the idea that shortly after the big bang, the universe underwent a very rapid, but short-lived, burst of hyper expansion. Cosmic inflation supposedly was faster than light. If redshifts were due to velocity, then this would require that matter moved faster than light during cosmic inflation, which would have violated special relativity. However, space may expand faster than light and carry matter with it without violating special relativity.

People cannot be faulted for having this wrong impression about universal expansion, because so many sources, including some astronomy textbooks, get this wrong. In discussing the redshifts of galaxies, it is tempting to appeal to the Doppler effect in explaining redshifts of galaxies. However, the Doppler effect is due to objects moving through space. Unfortunately, redshifts due to universal expansion are observationally indistinguishable from Doppler motion. Consequently, the observed redshift of a galaxy is the vector sum of its expansion (what we call the Hubble flow) and velocity in space. Only the latter is a true Doppler motion.

What Is the Universe Expanding Into?

In short, the universe isn’t expanding into anything. It is just getting larger.

In short, the universe isn’t expanding into anything. It is just getting larger. This misconception stems from the assumption that there must be something outside of the universe to expand into. Given that the universe normally is defined as the totality of physical existence, then there cannot be anything physical outside of the universe. If there is anything outside of the universe (such as some higher dimensionality), then it is entirely unknown to us and likely will remain so. Hence, there is nothing to expand into.

The common analogy of an expanding balloon illustrating the expansion of the universe probably helps fuel this misconception. The balloon obviously is expanding into the surrounding space, so it is easy to see why many people might think there must be something outside of the universe for the universe to expand into. Most analogies break down at some point. The problem with this analogy is that it is the surface of the balloon that represents the universe. But the surface of a balloon is two dimensional, and it expands into three-dimensional space that surrounds it. For that matter, the surface of the balloon contains a volume interior to its surface that is expanding along with the balloon. But space is three dimensional. As far as we know, there is no four-dimensional volume contained by the universe or a four-dimensional space into which the universe is expanding. But if there were, we could not see it, detect, or even fathom it.

Don’t Galaxy Blueshifts Disprove Expansion?

A few galaxies have blueshift, so how can this be if the universe is expanding? There are only three relatively large galaxies that have blueshift: M31, M33, and M81. In addition, there are several very small galaxies that have blueshift as well. None of these blueshifted galaxies are very far away, which is key to understanding what is going on. As mentioned in the previous section, the observed redshift of a galaxy is the sum of the galaxy’s Hubble flow and its motion through space. While all Hubble flow is in the positive direction (redshift), galaxy motion through space is as likely to be positive as negative (blueshift). The positive and negative spatial motions of galaxies probably are caused by gravity due to local distribution of matter and tend to cluster around zero. On the other hand, Hubble flow increases with increasing distance. Therefore, the negative spatial motion of some nearby galaxies can swamp the relatively small positive contribution due to Hubble flow, rendering an overall observed spectral shift that is negative (blueshift). But with increasing distance, the positive Hubble flow more than offsets any local negative contribution due to space motion, resulting in positive spectral shift (redshift). M31 and M33 are very close, comprising, with our Milky Way Galaxy, the Local Group of galaxies. The next closest group of galaxies, the M81 Group, also is dominated by three large galaxies, M81, M82, and NGC 2403. This group is close enough that one of its dominant members, M81, has a modest blueshift. A bit farther away is the Virgo Cluster, a very rich cluster containing many bright galaxies. The Virgo Cluster is far enough away that none of its galaxies have blueshift. Nor do any other more distant galaxies

Don’t Blueshifted Stars Disprove the Hubble Relation?

About half the stars in the Milky Way Galaxy have redshifts, while the other half have blueshifts. Upon learning this, some people think that this disproves the Hubble relation. While the Milky Way is large, compared to cosmic scales the galaxy is very small. Across the diameter of the Milky Way, the cosmic redshift (Hubble flow) amounts to about 2 km/s. This is much smaller than the typical orbital velocity of stars within the Milky Way. Therefore, the orbital velocities of stars within the Milky Way dominate any shift we see in their spectra. Since the sun orbits in the Milky Way galaxy along with all the other stars in the galaxy, we would expect the observed spectral shifts of stars to be evenly split between positive and negative. Indeed, they are. The important point is that the Hubble relation applies to galaxies, not to stars within our galaxy.

Can the Hubble Relation Be Used to Find Distance?

Many people understand that since the Hubble law relates galaxy redshift to distance, then the Hubble relation can be used to find a galaxy’s distance. All that is necessary, besides a measurement of the galaxy’s redshift, is the Hubble constant, the slope of the Hubble relation. Division of the galaxy’s redshift by the Hubble constant yields the distance. Related to the previous discussion, some people mistakenly believe that the distances of stars can be determined this way too. However, as discussed above, the Hubble relation applies to galaxies, not to stars within our galaxy.

Is the Hubble Relation the Only Way to Determine Distances of Galaxies?

While the Hubble relation may be used to infer a galaxy’s distance, it is a common misconception that it is the only way to determine distances of galaxies.

While the Hubble relation may be used to infer a galaxy’s distance, it is a common misconception that it is the only way to determine distances of galaxies. There are numerous alternate methods of finding galaxy distances, most of them relying upon standard candles, bright objects within galaxies for which we think we know the intrinsic brightness. The only drawback is that most standard candles can be seen only out to a limited distance (at this time typically 50 million light years or so). The only exception is type Ia supernovae. The problem with type Ia supernovae is that they are relatively rare, happening only a few times per century in any galaxy. The advantage to using the Hubble relation to find distance is that it can be used with any galaxy bright enough to obtain a spectrum.

Doesn’t the Hubble Relation Prove We are at the Center of the Universe?

Therefore, an observer in any galaxy would see all the other galaxies moving away from himself. Consequently, all observers have the illusion that they are the center of the universe.

This misconception arises from the misunderstanding of cosmic expansion being due to velocity. This leads to the mistaken belief that we must not be moving, and hence everything else in the universe must be racing away from us, placing us at the universe’s center. However, if it is the space of the universe that is expanding, then at every location in the universe everything else would appear to be moving away. Consider an analogy to raisin bread dough as it proofs, or rises. The raisins represent individual galaxies, and the rising dough represents the expanding universe. The raisins do not increase in size, so they do not share in the rising of the dough. But the raisins are carried along by the rising dough, so that to each raisin, it would appear as if all the other raisins were moving away from it. In similar fashion, the galaxies don’t share in universal expansion, but they are carried along by the expansion of the universe. Therefore, an observer in any galaxy would see all the other galaxies moving away from himself. Consequently, all observers have the illusion that they are the center of the universe.

Don’t Quantized Redshifts Prove That We Are at the Center of the Universe?

Since the 1970s, American astronomer William Tifft has published papers indicating that galaxy redshifts are not uniformly distributed, but rather tend to clump around discrete values, such as multiples of 72 km/s. If galaxy redshifts are cosmological, then the most straightforward interpretation is that there are concentric shells of galaxies surrounding the earth. Such a structure would be difficult to reconcile with modern cosmology and would seem to indicate that the earth is in a special location, even the center of the universe.

But is there a different possibility? The expectation of a uniform distribution of redshifts is based upon the assumption that matter is uniformly distributed in space. However, observations make it abundantly clear that rather than being uniformly distributed, matter is very clumpy, organized into long strings and filaments of galaxies. As we look through multiple sheets of galaxies, the galaxies appear clumped on those sheets with relatively few galaxies in between. This gives the impression that galaxies are clumped around our location, but it is likely that any observer anywhere in the universe would see the same thing.

Doesn’t Arp’s Work Disprove the Expansion of the Universe?

The late astronomer Halton Arp spent decades arguing against a slavish application of the Hubble relation. He presented evidence of what he thought were examples of redshifts that were not cosmological. For instance, he published photos of pairs of galaxies that appeared to be interacting. If the galaxies truly were interacting, then they must be the same distance. But the redshifts of the pairs of galaxies were discordant, meaning that they had very different values. Application of the Hubble relation would result in very different distances to the members of each pair, meaning that they couldn’t be interacting. Many people found Arp’s argument compelling, but there is considerable question about the supposed interactions. For instance, in 1971 Arp produced a deep, long exposure photograph of the galaxy NGC 4319 and the active galaxy Markarian 205. There appeared to be a faint nebulous bridge between the two, indicating a physical connection. Arp considered this to be one of his best examples of discordant redshifts. But other astronomers thought that the faint bridge of light between the two was an artifact of the photography process. Additional ground-based photographs did not help much. In 1992, shortly after the Hubble Space Telescope (HST) went into use, the HST was used to photograph this pair. There was no luminous bridge. Furthermore, a detailed study using HST data produced strong evidence that Markarian 205 truly lies far beyond NGC 4319, and so the galaxies were not connected at all.

Many creationists loved Arp’s work, because they thought that his work meantquaw that the universe is not expanding. If the universe isn’t expanding, then the big bang model cannot be true.

Many creationists loved Arp’s work, because they thought that his work that the universe is not expanding. If the universe isn’t expanding, then the big bang model cannot be true. However, this is to misunderstand Arp’s work. Arp thought that the universe is expanding, and so he thought that most galaxy redshifts are cosmological and thus could be used to find distance. Arp merely objected to the belief that all galaxy redshifts are cosmological and hence follow the Hubble relation.

What was Arp’s motivation? Arp was committed to the steady-state model, the minority viewpoint that the universe is eternal, has always been expanding, and always will expand. But in the early 1960s, astronomers discovered quasars: very blue, faint, point-like objects with very high redshifts. Assuming that quasar redshifts are cosmological results in quasars being very far away. But this implies that quasars be very bright, in most cases far brighter than entire galaxies. From their point-like appearance, quasars must be very small. This requires a very special source of power, with the only candidate being supermassive black holes gobbling vast amounts of matter. There are no low-redshift quasars, but their numbers increase with greater redshift. If redshifts are cosmological, then there are no local quasars, though quasars are common at great distance. Most astronomers attribute this to evolution of galaxies—quasars are very young galaxies that soon evolve into mature, less active galaxies. If the speed of light is constant, then distance reflects look-back time. For instance, we see a galaxy five billion light years away not as it now exists, but how it existed five billion years ago. According to the standard interpretation, all nearby galaxies have settled down into maturity, but very distant galaxies are very young and active, so we classify them as quasars. It is this evolution of galaxies implied by quasar being at great distance that Arp couldn’t accept. In the steady-state model, the universe is eternal and hence does not evolve. Galaxies are born and age, but they are replaced by newer galaxies. Therefore, galaxies far away cannot look fundamentally different than nearby galaxies. Consequently, Arp thought that quasars aren’t distant, young, bright galaxies. Rather, he thought that they were relatively close by and were objects ejected from nearby galaxies.

Again, Arp never rejected the concept of an expanding universe. If he had, then the steady-state model wouldn’t work anymore than the big bang would. Instead, Arp argued that not all redshifts of extragalactic objects are due to universal expansion. Creationist often misunderstand what Arp was trying to prove. And creationists often don’t know that many of the things Arp argued have been proved wrong.

Doesn’t the Expansion of the Universe Ultimately Lead to Big Bang Cosmology?

It is true that if the universe is not expanding, then the big bang model cannot be correct. But this may be throwing the baby out with the bathwater. The big bang model is just one possible outcome of an expanding universe. For instance, the steady-state model was based upon an expanding universe too. If the universe is indeed expanding, then omitting that detail would doom any attempt to establish a biblical cosmology. One might reinterpret the Hubble relation, but until a viable alternate explanation comes about, expansion remains the best interpretation of the Hubble relation.

Where Did the Big Bang Happen?

This misconception stems from an improper understanding of the big bang model. Most people think of the big bang as being an explosion of matter and energy in space (see above). They further think of this explosion expanding outward into space and will continue to do so indefinitely. But according to the big bang model, the universe was not just the sudden appearance of matter and energy: the big bang was the sudden appearance of space and time too. That is, the big bang didn’t happen at some point in the universe. Rather, the big bang happened everywhere. It’s just that everywhere was much smaller back then. As the universe expands, the matter and energy doesn’t fill space that previously was empty. Instead, in the big bang model, the universe began filled with matter and energy, but that matter and energy gets less dense as the universe expands.

What Was Here Before the Big Bang?

According to the big bang model, just as matter, energy, and space began with the big bang, so did time.

This misconception is related to the misconception discussed above. According to the big bang model, just as matter, energy, and space began with the big bang, so did time. Hence, there was no time prior to the big bang. In fact, since time supposedly began with the big bang, the concept of “before the big bang” has no meaning. And since space didn’t exist prior to the big bang, the concept of “here” as in the question above has no meaning either. I often answer this question by saying that this question makes no sense, because, “According to the big bang model, here wasn’t here then and then wasn’t then then either.” Or as Stephen Hawking once described this question as "like asking what is north of the North Pole?"

Does the Big Bang Prove That God Exists?

As mentioned in the introduction, there are Christian apologists and scientists who make the argument that the big bang proves that God exists. Their reasoning is that all effects must have a cause, so the effect of the big bang must have had a cause, and the only candidate for that cause is God. However, there is a flaw in this argument. The argument of causality operates in time. It is obvious that the cause of an effect cannot follow the effect in time. It may be possible for a cause and effect to be simultaneous, but all causes that we see in the world precede the effects they cause. Therefore, appeal to an effect that is simultaneous with its cause is not based upon solid observation. Furthermore, if a cause and effect are simultaneous, can one truly say with confidence which is the cause, and which is the effect? Hidden in this reasoning is the assumption that time existed prior to the big bang. However, as discussed above, this is not what the big bang model posits. People who make this argument for God’s existence present what they think is irrefutable scientific evidence for the big bang and then substitute their version of the big bang model somewhere between the science and the philosophical conclusion. These people fail to understand that the modern big bang model is an uncaused cause. It is superfluous to assert a second uncaused cause (God) into the argument.

How Could the Solar System Have Come from a Big Bang?

This misconception is related to the previously discussed one and the big bang being an explosion. The big bang purports to explain the origin and structure of the universe to a sudden appearance of space, time, matter, and energy. The big bang supposedly happened 13.8 billion years ago. According to the widely accepted hypothesis of how the solar system came about, a cloud of gas and dust began to condense under its own gravity a little more than 4.5 billion years ago, 9 billion years after the big bang. The big bang model purports to explain where the universe came from, while the nebular hypothesis attempts to explain the origin of the solar system. The only thing the two have in common is they are naturalistic origin scenarios in astronomy.

Isn’t Dark Matter a Rescuing Device for the Big Bang?

Many discussions of the big bang model include the inclusion of dark matter, so it is easy to understand that dark matter might be a fix to some problems that the big bang model has. However, the evidence for dark matter predates the wide acceptance of the big bang model, and it had nothing to do with the big bang. That evidence came in the 1930s with observations of motions of galaxies in clusters. The data showed that the galaxies were moving far too fast to account for orbital motion required by the amount of gravity implied by the brightness of the galaxies in the clusters. The discrepancy suggested that the amount of visible mass was only about 10% required to explain the orbital motion. In 1939, the first rotation curve of a single galaxy indicated that only about 10% of its mass was showing up too.

Astronomers largely ignored these strange results for four decades. Finally, in the 1970s, a pair of astronomers published a series of papers demonstrating that the rotation curves of most galaxies showed the same thing—far more matter present in galaxies than could be accounted for by the light that we see. In most cases, the mismatch was again a factor of ten. As odd as it seemed, it appeared that only about 10% of the matter of the universe was revealing itself by emitting light. Thus, by the 1980s, astronomers began to realize that much of the mass of the universe was dominated by this invisible, dark matter. There has been much discussion ever since as to what dark matter is.

As late as astronomers were in grasping the evidence for dark matter, cosmologists were even more tardy. It wasn’t until the 1990s that cosmologists realized that if gravity is the dominant force in the universe, then any cosmology that didn’t include all the matter (and hence gravity) in the universe is insufficient. Once dark matter was included in big bang models, it became another parameter used to solve problems and fit to the data. From the discussion of dark matter within the context of the big bang, it is easy to see why it might appear as though it was an ad hoc lifeline. But this lifeline was already in existence long before cosmologists began to make use of it.

Conclusion

I have discussed several common misconceptions about modern cosmology and the big bang model. Some of these misconceptions are common among laypeople in general, but some are specific to biblical creationists. In their zeal to argue against the big bang model, some creationists may have strayed into some of these misconceptions. However, it is important that we ensure that our arguments are sound. There are many other, legitimate problems that the big bang model suffers from. They include:

• The lack of magnetic monopoles
• The asymmetry between matter and antimatter
• The horizon problem
• The flatness problem

Furthermore, there is much discrepancy between the big bang model and what Scripture says about the origin of the world. These include the issue of time and the order in which things were introduced. But perhaps the most significant biblical problem for the big bang model is that it is the ultimate purely physical explanation of origins. The big bang is an attempt to give a reason totally apart from God why anything exists. Christians ought to avoid any reasoning based upon atheism.