Previous writings here on the blog have included:
2.1 Relationships between Science and Faith
2.2 Critical Realism and the Coherence of Truth
2.3 Approaches to Scripture
3.1 General and Special Relativity
8.1 Approaches to Genesis 2-3
8.2 Situating Genesis 2-3
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As the vastness of the universe became more and more apparent over the course of the twentieth century, three primary theories emerged to account for its origins and ongoing nature. At the middle of the century, the favorite was the so-called steady state theory, championed to great effect by individuals like Fred Hoyle. A small minority thought the math of general relativity might point to a beginning of the universe with something like a "big bang." The name "big bang theory" was actually given to this approach in ridicule. However, after it became clear that this was the most likely beginning to the universe, some suggested an ongoing oscillating big bang so as to avoid the need to invoke something like a Creator. [1]
textbox: Three Models:
steady state theory -- the universe has no beginning and matter is constantly being created as space expands
big bang theory -- the universe began at a point in the past in a dense hot state that has been expanding and cooling ever since
oscillating big bang theory -- the universe begins, expands, contracts, expands again endlessly
3.2.1 Steady State Theory
After Einstein introduced the general theory of relativity, it was not long before individuals like Alexander Friedmann (1922) and Georges Lemaître (1927) recognized that the theory could point to a beginning to the universe followed by cosmic expansion. Einstein himself did not find this possibility appealing. He preferred a static universe that neither expanded nor contracted but that more or less stayed the same for all time. To counteract gravity and keep the universe static, he introduced a "cosmological constant" to his equations.
However, in 1929 Edwin Hubble discovered that the universe was expanding -- everywhere. As a light-emitting object moves away, the frequency of the waves gets elongated (like the Doppler effect when a siren is moving away from you). The result is what's called a "red shift." Galaxies all appeared to be moving away from one another, as though space itself were stretching.
So, despite Einstein's attempt with the cosmological constant, the scientific community now had to come to grips with a universe that wasn't static at all. [2] In fact, it might very well have had a beginning. Georges Lemaître had seen this theoretical possibility of the math in 1927. He was both a scientist and a Belgian Roman Catholic priest. He saw this evidence as support for the idea of God as a Creator.
Enter Hermann Bondi, Thomas Gold, and Fred Hoyle in 1948. Finding the possibility of a "Big Bang" at the beginning distasteful, they proposed a "steady state theory." The idea was that as the universe expanded, the average density of the universe stayed the same by creating matter to fill the gaps. They proposed that about every billion years, one hydrogen atom came into being for every cubic meter in the universe. They suggested that matter is continuously being created and thus that there did not need to be a beginning (or a Creator). Thus, the universe had no beginning or end in time.
Hoyle was known for his charismatic personality. In fact, he was the one who coined the expression "big bang" for the idea of a beginning. He regularly appeared on the radio and made it easy for the public to believe that his preferred cosmological option was the best of the alternatives.
3.2.2 The Big Bang Theory
As early as 1922, Alexander Friedmann recognized that Einstein's relativity equations could be interpreted to suggest a beginning to the universe in a very dense state. Friedmann's life unfortunately was cut short in Russia by typhoid, but seven years later the Belgian scientist Georges Lemaître independently came to the same conclusion.
With the confirmation of the universe's expansion in 1929, the possibility that the universe began with a "big bang" became even more plausible. Although the expression was originally one of derision, the name stuck. Nevertheless, this option remained unpopular among naturalists until the mid-1960s. Naturalism insists on explaining all the phenomenon of the world without recourse to the existence of the supernatural or spiritual. Many naturalists resisted the idea of a cosmic beginning, since a universe with no beginning seemed to remove the need for any first cause or Creator.
Nevertheless, events that unfolded in 1965 finally settled the debate. Early, in the 1940s, scientists like George Gamow had suggested that if the universe did begin in a hot, dense, fiery state, then the leftover radiation from that fireball should be detectable still today. As space stretched, the leftover radiation would stretch into the microwave frequencies and would form a sort of cosmic microwave background (CMB) everywhere in the universe, with a temperature a few degrees above absolute zero.
radiation. They were working on a radio telescope for Bell Labs, but wherever they pointed the telescope in the sky, it was picking up a faint microwave hiss. They tried everything to eliminate possible noise sources, even cleaning out pigeon droppings inside the antenna. But the signal remained.
When Robert Dicke and Jim Peebles at nearby Princeton University heard about the situation, they immediately suspected that Penzias and Wilson had come upon the very "afterglow of creation" that for which they were planning to test. This puzzling signal was exactly what Gamow and others had predicted if the universe had begun with a "big bang." Hoyle and others were unable to account for it with their steady state theory, and the big bang theory became the primary theory for the universe's origin.
As we will see in the section on the inflationary universe, the current thinking is that the cosmic microwave background comes from around 380,000 years after the beginning, when the universe cooled enough for photons to be released universe wide. "Let there be light," you might say. If the universe were infinitely old, the background radiation would have already dissipated. The CMB is thus strong evidence that the universe had a beginning.
3.2.3 The Oscillating Big Bang
Naturalism insists on explaining the phenomena of the world without recourse to the supernatural or spiritual. However, the Big Bang theory suggested that the universe had a beginning, which raised the question of why the universe began. Theists were all too ready with an answer -- a Creator. This left the naturalist to ask what other explanation there might be.
One option came to be known as the "oscillating" big bang. As early as the 1930s, Richard Tolman had explored the possibility of "cyclic" universes. In the late 1900s, the theory revived of a universe that was in a constant process of rapid expansion, then contracting into a crunch, then expanding again in an endless, eternal cycle. In this way, the universe would have no beginning or ending. It would just be one endless cycle of expansion and contraction -- bang and crunch, bang and crunch for all eternity.
The main problem with the theory was entropy, the tendency of systems to increase in disorder and to lose heat. Each recycled universe would thus have less usable energy than the previous one. The result is basically a countdown to a universe without order -- not an infinitely repeatable cycle. Further, by the early twenty-first century, it was clear that there was not enough matter in the universe for its gravity to pull it back into a crunch. Indeed, the expansion of the universe seems to be accelerating. Its destiny could actually be a cosmic "rip" rather than a cosmic "crunch."
[1] Einstein preferred a static model in the early twentieth century, with the universe always being more or less as it is today.
[2] Einstein later called the constant a blunder, although it did turn out to be part of the equation.
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