Overview of the Big Bang Theory in Astronomy

Within the discipline of astronomy, the big bang theory (not to be confused with the popular television show) is a theory of the origins of the physical universe we live in today. The purpose of the present sample essay provided by Ultius is to develop an overview of the big bang theory. The essay will begin with a description of the main idea of the big bang theory. Then, it will consider how the big bang theory was formulated in the first place. After this, the essay will discuss the implications of the big bang theory for the shape and the fate of the current universe. Finally, the essay will reflect on correspondences between the big bang theory on the one hand and the insights of religious scriptures on the other. 

Description of the Theory

The core idea of the big bang theory is a fairly simple one. Williams has articulated this idea in the following way: "the Big Bang hypothesis states that all of the current and past matter in the Universe came into existence at the same time, roughly 13.8 billion years ago. At this time, all matter was compacted into a very small ball with infinite density and intense heat called a Singularity. Suddenly, the Singularity began expanding, and the universe as we know it began" (paragraph 3). It is almost impossible to imagine the singularity itself, insofar as the singularity would have lacked all dimension. The idea here is that it is the explosion and expansion of the singularity was the cause of the spacetime universe itself, meaning that the singularity itself would have in a sense existed outside of the bounds or categories of space and time. Again, while this can be effectively theorized, it is difficult to imagine, insofar as the human mind has trouble imagining things without making use of space and time. 

Likewise, the big bang theory would seem to beg the question of what existed before the big bang happened. This would be a meaningless question however, due to the simple fact that before the big bang, there was no such thing as time, which means that in ordinary terms, there was actually no such thing as a "before" the big bang. It is nevertheless possible that something did happen before the big bang; but in practical and scientific terms, it would be virtually useless to theorize about that prior state of affairs. Stephen Hawking has stated the following in this regard: "Since events before the Big Bang have no observational consequences, one may as well cut them out of the theory, and say that time began at the Big Bang. Events before the Big Bang, are simply not defined, because there's no way one could measure what happened at them" (paragraph 7). In other words, it is possible that there was some kind of other reality or universe that existed before the big bang; but the big bang is the genesis of the current universe as we know it; so, it is virtually impossible to investigate what happened before the genesis of this universe, while living within the context of this universe itself.

The nature of this discussion would seem to veer into metaphysics, or even religion: the big bang would seem be an event possessing an almost mystical cadence. Nevertheless, the big bang theory is solid science, which means that there is actual empirical evidence that has been gathered and verified over time that serves to logically prove the existence of the phenomenon. There are other theories about the origins and the nature of the universe; but today, the vast majority of scientists accept the big bang theory, due to the fact that this theory is the one that is most strongly supported by the extant empirical evidence regarding the subject. At this point, then, it may be worth turning attention to the actual science underlying the big bang theory, or why scientists "believe" in the theory in a way that is substantially different from believing in a religious proposition. 

Genesis of the Theory

The scientific evidence in favor of the big bang theory has accumulated since the 1920s. The magazine National Geographic has written the following regarding the beginnings of the theory: "A Belgian priest named Georges Lemaítre first suggested that the big bang theory in the 1920s when he theorized that the universe began from a single primordial atom. The idea subsequently received major boosts by Edwin Hubble's observations that galaxies are speeding away from us in all directions, and from the discovery of cosmic microwave radiation by Amos Penzias and Robert Wilson" (paragraph 6). Lemaítre's idea was more of a creative one in nature than an objective fact; however, the findings of the scientists began to show that there may be empirical truth to be found in the idea. For example, the objective fact of universes speeding away would be consistent with the big bang theory and to an extent could only be explained by the big bang theory. Retrospective logic would seem to indicate that if this movement is happening, then the entire universe must have been concentrated into a singular central point, somewhere in the very distant past. 

Likewise, the observation of microwave radiation is also consistent with and explained by the big bang theory: "Theories predicted that after a Big Bang, there would have been a tremendous release of radiation. And now, billions of years later, this radiation would be moving so fast away from us that the wavelength of this radiation would have been shifted from visible light to the microwave background radiation we see today" (Cain, paragraph 9). Likewise, the chemical composition of the universe as measured through relevant methods is also consistent with the idea that the universe was once concentrated into a singular point, and that that point more or less acted like the core of a star. Observations like these provide the empirical and scientific foundations for the validity and credibility of the big bang theory.

It must still be admitted, however, that the big bang theory does leave at least one important question unanswered: that question consists of what triggered the big bang into occurring in the first place. As National Geographic has pointed out, "several answers have been proposed to address this fundamental question, but none has been proven—and even adequately testing them as proven to be a formidable challenge" (paragraph 9). In all likelihood, this question will probably remain a mystery from the empirical perspective, due to the simple fact that it seems to verge on a teleological question. That is, asking what caused the big bang is tantamount to asking why the big bang happened, or the reasons underlying the existence as opposed to of the universe. As Iyer has argued, science itself is methodologically unequipped to handle this sort of inquiry (82-83). Science is meant to make empirical observations about what actually exists through research or sending probes out into the solar system; it is not meant to explore the metaphysical question of why something—including the universe as a whole—exists. 

Implications for the Universe

The big bang theory implies that the universe, since its genesis, has been expanding outward from a singular point. This begs the question of whether this expansion will go on forever. In this context, a concept that corresponds to the concept of the big bang is that of the big crunch. As Luntz has put it: "One theory for dark energy suggests that the universe may not expand forever, but instead collapse in a 'big crunch,' after which time will cease to exist. Now, according to a new study, this could happen much sooner than anyone expected—although still on the order of billions of years away" (paragraph 1). The main idea here is that at some point, the gravity within the universe will become such that the universe will no longer keep expanding but will rather start contracting in on itself. This will eventually return to the universe to the singular point that existed at the time of the big bang; and the return to that point would signify the end of the universe as it is currently known. 

On the other hand, the theory that the universe will in fact expand forever also does not provide a good long-term prognosis: scientists suggest that if this were to happen, then known universe may end in a big freeze instead of a big crunch. Just as the big crunch is premised on a reversal in the gravity of the universe, the big freeze is premised on a reversal in the energy of the universe on the other. More specifically, if the universe were to keep expanding forever, this would eventually result in a situation where the energy within stars will burn out, resulting in large scale energy loss. Without the stars, the entire structure of the universe would more or less collapse; and in any event, it would become impossible for life as we know it to exist anywhere within the universe. The only optimistic possibility, then, is the steady state theory of the universe, which suggests that the universe will neither crush itself nor expand forever, but will rather maintain a perpetual dynamic equilibrium for the indefinite future. 

Theory and Scripture

The big bang theory has uncanny resonances with the insights of the religious scripture known as the Bible. In particular, this is what it written at the very beginning of the Bible, within the Book of Genesis: "In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters. And God said, Let there be light: and there was light" (1:1-3). This is virtually identical with the account provided by the theory of the big bang, except that it also provides a theological explanation for the creation of the universe. The theory suggests that at first there was nothingness, and then huge energy (i.e. light) exploded out of this nothingness. The Bible also suggests that this what happened, but adds that it happened because God wanted this to happen. Science, qua science, cannot make any meaningful comment on this latter question; it can only plead ignorance. 

Likewise, the big bang theory also finds uncanny correspondences in the Hindu scriptures known as the Vedas. The blogger Sanskriti, for example, has translated one passage of the Vedas in the following way: "Darkness was hidden by darkness in the beginning. With no distinguishing sign, all this was water. The life force that was covered with emptiness That ONE arose through the power of heat" (paragraph 6). Again, translated into empirical language, the account of the Vedas would seem to be in virtually total correspondence with the account of the theory of the big bang: at first there was nothing, but then something moved through the power of heat, and the world came into being. Again, though, the Vedas, like the Bible, provide a teleological explanation that eludes the domain of science: there was an agent—God, by any other name—who made this whole show happen. 

Conclusion

In summary, the present essay has consisted of an overview of the theory of the Big Bang within the discipline of astronomy. The essay began with a description of the theory, proceeded to consider the empirical evidence in support of theory, turned to a discussion of the implications of the theory for the shape and fate of the universe, and finally reflected on the correspondences between the theory and religious scriptures. A key point that has been made here is that while the theory of the big bang provides a description of the genesis and history of the universe that is well-supported by the relevant empirical evidence, this should not be confused with a teleological explanation of why this whole thing happened in the first place. If one wants that, one may be well-advised to turn to relevant religious scriptures, which largely correspond with the scientific theory but also go further and state why the world even happened at all.

Works Cited

The Bible, King James Version. 

Cain, Fraser. "What Is the Evidence for the Big Bang?" Universe Today. 18 Nov. 2013. Web. 14 Jun. 2014. <http://www.universetoday.com/106498/what-is-the-evidence-for-the-big- bang/>. 

Hawking, Stephen. "The Beginning of Time." Author, n.d. Web. 14 Jun. 2016. <http://www.hawking.org.uk/the-beginning-of-time.html>.

Iyer, Sethu A. Testament: An Invitation to Lucid Romance. Austin: CreateSpace, 2016. Print. 

Luntz, Stephen. "New Study Suggests We're Approaching the 'Big Crunch.'" ILF Science. 24 Mar. 2015. Web. 14 Jun. 2016. <http://www.iflscience.com/physics/big-crunch-back-possible-end-universe/>. 

National Geographic. "Origins of the Universe: An Expanding World." Author, n.d.. Web. 14 Jun. 2016. <http://science.nationalgeographic.com/science/space/universe/origins-universe-article/>. 

Sanskriti. "Vedic and Scientific Explanation of the Big Bang Theory." Author, 16 May 2016. Web. 14 Jun. 2016. <http://www.sanskritimagazine.com/indian-religions/hinduism/vedic-scientific-explanation-big-bang-theory/>. 

Williams, Matt. "Big Bang Theory: Evolution of Our Universe." Universe Today. 17 Dec. 2015. Web. 14 Jun. 2016. <http://www.universetoday.com/54756/what-is-the-big-bang-theory/>.