The Expansion of the Universe as a Current Scientific Clock

By Peter Fischer

It is generally accepted that the Big Bang, some 13-15 billion years ago, marked the beginning of the expansion of the Universe. We know this occurred 13-15 billion years ago because the expansion of the Universe offers several natural clocks with which to date it. The first and more notable of these clocks is the red shift, or Doppler Effect, and the second is the presence of cosmic microwave background radiation. The expansion of the universe and its natural clocks (which will be explained below) has resulted in much debate among Creationists, with some incorporating these scientific conclusions into their beliefs, and others choosing to deny the Big Bang and expanding universe entirely.

Dating the Universe

universeEdwin Hubble, a 1920s astronomer, first discovered evidence of an expanding universe when he noted that all visible galaxies appear to be moving away from each other. Based on a property of light called the red shift, he noticed that the farther away a galaxy was, the faster it was receding. This relationship, known as Hubble's Law, has been repeatedly verified (Dalrymple 2004:189). In 1927, Georges Lemaitre, a Belgian astronomer, noted that this observation is most easily explained if the Universe started at a definable time in the past with a violent expansion of matter and energy that was originally highly compressed and intensely hot (Dalrymple 2004:189). Thus, the idea of the Big Bang was born.

The most important confirmation of the Big Bang came from a discovery in 1965 by Arno Penzias and Robert Wilson, two engineers working for Bell Laboratories. They discovered radiation from space, called "the cosmic microwave background," that permeates the Universe. This background radiation has all the characteristics it was predicted to have if the Universe started with the Big Bang and has since been expanding (Dalrymple 2004:15).

As previously stated, both the expansion of the universe and the background radiation can be used as clocks to date the age of the universe. In the expansion of the Universe, Hubble's law relates velocity to distance, and distance divided by velocity equals time. Scientists can measure the velocity of distant objects as they move either toward or away from Earth using the Doppler Effect (Dalrymple 2004:189). This clock assumes that the Universe expands uniformly or by known changes in velocity, and that the distance to other galaxies has been accurately estimated (Dalrymple 2004:191-93). As any source of light moves toward or away from an observer, there is a velocity-dependent shift in both the wavelength and the frequency of the light. For objects moving away, the wavelength is lengthened and the frequency is decreased (Dalrymple 2004:189). Because wavelength defines color, a receding source of light has its spectral lines shifted toward the red end of the spectrum.redshift Using this red shift, the velocities at which galaxies are receding from the Milky Way and from each other can be measured, and the time required for the matter of the Universe to have expanded from a point of infinite density can be calculated. The most recent calculations, which take into account the non-uniform expansion caused by the mass of the Universe and by vacuum energy, give ages for the Universe in the range of 13-15 billion years (Dalrymple 2004:211).

The second clock, cosmic background radiation, involves the analysis of the warmer and cooler spots in the cosmic microwave background. This microwave radiation is thought to have originated in the Big Bang, and it is a measure of the average temperature of the Universe, which has been cooling as the Universe has expanded. To elaborate on this, sound waves in the forming Universe left their imprint on the microwave radiation in the form of slightly warmer and cooler spots, which correspond to regions where the radiation is being compressed and expanded (Dalrymple 2004:194). The size of these spots is uniform throughout the Universe. The older the Universe is, the farther apart these spots should be and the smaller they should appear. An analysis of these warmer and cooler spots of background radiation gives an age for the Universe of 14 plus or minus 0.5 billion years (Dalrymple 2004:194).

Although some aspects are still in the process of being understood, a basic overview of the early history of the Universe is as follows. At the very beginning, according to the Big Bang theory, the temperature and density of the Universe were infinite, and it was filled with tremendous energy. The Big Bang initiated expansion. This consisted of a decrease in density accompanied by cooling, both of which are continuing to this day. Within the first 10 seconds or so after the Big Bang, the principal subatomic particles were formed. About 300,000 years later the temperature decreased to 10,000 K and the first simple atoms formed. The subsequent history of the Universe involved continued cooling, continued expansion and a decrease in average density, and the condensation of dust and gas into galaxies, stars, and planets (Dalrymple 2004:15).

Creationist Interpretations of the Big Bang

Creationist Hugh Ross accepts this conventional science and integrates it into the Biblical account. He describes the Big Bang as "an immensely powerful yet carefully planned and controlled burst of creation" (Ross 2004:139). From a source beyond the cosmos, time, space, matter, energy, and the physical laws that govern them came into existence in an instant. That source, according to Ross, is God. Ross' proof here is the "extreme fine-tuning not only in the laws and constants of physics but also in the gross features of the universe, such as its expansion rate, uniformity, total mass, and relative numbers and masses of different fundamental particles. The possibility of life's existence and survival depends on the fine-tuning of all these features" (Ross 2004:140).

Moreover, Ross points out Biblical scripture that explicitly and repeatedly states two fundamental features of the Big Bang: a transcendent cosmic beginning in the finite past and continuous cosmic expansion (Ross 2004:142). In one example, Ross cites Isaiah 42:5 which refers to God as "He who created the heavens and stretched them out." Ross also cites additional passages from Isaiah and Job, which make reference to "the stretcher of the heavens" and imply continual or ongoing expansion (Ross 2004:143).

On the other side of the Creationist debate concerning the origin of the Universe is the Institute for Creation Research (ICR) and other fundamentalist Creationists like Kurt Wise. Unlike Ross, who accepts the science behind the Big Bang, Wise and the ICR scientists believe in a young-age creation model, where God created the universe in a complete, mature form, meaning the universe did not have to develop into its final form from an event like the Big Bang. Because the universe does not have to develop or evolve, fewer evidences have to be explained in the young-age creation model. It is, as Wise (2002:81) contends, a simpler hypothesis. Wise believes that, in its simplicity, a young-age creationist model provides the only possible explanation that is in harmony with the Bible.

Wise goes further to discount the Big Bang. He notes that although the Big Bang is well evidenced, it cannot be true for the following reasons: According to scripture the universe is only 6,000 years old, God created the heavens and the earth during the literal creation week, and that the cosmic radiation is too uniform - more so than the distribution of matter in the universe (Wise 2002:81). Wise does have a valid point with the radiation being too uniform, as this is one aspect science has yet to fully explain. However, this is certainly not enough to discredit the Big Bang theory altogether.

The Institute for Creation Research tries to further discredit the Big Bang theory. They state that based on the Big Bang theory, cosmologists predicted that the distribution of matter throughout the universe would be homogeneous (Gish 1991). Thus, it was postulated that the distribution of galaxies in the universe would be essentially uniform: in every direction one should see the same number of galaxies. As the ICR explains, recent research has revealed massive super clusters of galaxies and vast voids in space (Gish 1991). In other words, the distribution is not homogenous. Nevertheless, this creationist claim can be explained by vacuum energy, otherwise known as dark energy, which is a force that repels objects and counteracts gravity. Only about 4% of the total mass in the universe can be seen directly, according to current theory. The rest of the mass in the Universe is thought to be composed of this dark energy and dark matter (Goldsmith 2000:61).

Although Young-Earth Creationists are quick to seek problems with the Big Bang model, no alternative theory has been presented to explain the supporting data. At the same time, both the ICR and Kurt Wise continue to ignore evidence for the Big Bang. For instance, these Young-Earth Creationists generally accept the great size of the universe, but they are forced to appeal to an 'appearance of age' or a change in the speed of light to account for stars and galaxies over 6,000 light years away being visible from earth (Ross 2004:65; Niessen 1983). Ultimately, both the red shift and background radiation serve as well-established natural clocks for dating the age of the Universe between 13-15 billion years. Regardless of how Creationists characterize the Big Bang theory and the expansion of the universe, there are no legitimate competing models that explain the size and character of the Universe. The Big Bang and the subsequent expansion of the Universe is the most valid explanation that science has to offer.

  1. Dalrymple, Brent G. 2004. Ancient Earth, Ancient Skies. Stanford: Stanford University Press, 15, 189-94, 211 p.
  2. Gish, Duane. 1991. The Institute for Creation Research. Impact Article #216: The Big Bang Theory Collapses. Article Date: June 1, 1991.
  3. Goldsmith, Donald. 2000. The Runaway Universe. Cambridge: Perseus Publishing, 61 p.
  4. Niessen, Richard. 1983. The Institute for Creation Research. Impact Article #121: Starlight and the Age of the Universe. Article Date: July 1, 1983.
  5. Ross, Hugh. 2004. A Matter of Days. Colorado Springs: NavPress, 139-143 p.
  6. Wise, Kurt P. 2005. Faith, Form, and Time. Nashville: Broadman & Holman, 81 p.