Exactly when in the history of the universe’s expansion from the cosmic creation event did the first stars form
As noted in parts 1, 2, and 3 of this article series, examining cosmic history can test the biblical doctrine of cosmic creation in five important ways:
- Was the universe created?
- How was the universe created?
- Was the universe supernaturally designed in advance for life and human beings in particular?
- How successful was the Bible in predicting future scientific discoveries about the universe?
- How old is the universe?
In parts 1, 2, and 3, I explained how new techniques provided additional chronometers for dating various stages in the life cycles of star clusters, galaxies, and quasars. In this article, the fourth and last in this series, I will discuss chronometers that determine even earlier epochs in the development of the universe.
Fundamental to all of the biblically predicted big bang creation models1 is the crucial question: exactly when in the history of the universe’s expansion from the cosmic creation event did the first stars form. One way to get a handle on the cosmic date for the first stars is to measure the redshift of the most distant known objects in the universe. Only extremely high luminosity objects will be detectable at great distances. Currently, gamma-ray bursters (see figure) rank as the brightest objects astronomers can see.
In a recent issue of the Astrophysical Journal Letters a team American and Canadian astronomers reported on the discovery of radio afterglow emission from gamma-ray burster GRB 090423, which exploded at a redshift of 8.3.2 This object manifests the highest known redshift in the universe by a wide margin. The redshift measure places GRB 090423 at a distance of 13.11 billion light-years, corresponding to a time when the universe was only 620 million years old.
However, the afterglow properties of GRB 090423 are not sufficiently different from other gamma-ray bursters to suggest that it arose from the explosion of a metal-free star. Astronomers know that the first stars, labeled population III stars, must have been metal-free since the nuclear furnace of the big bang creation event produced only helium and trace amounts of lithium, boron, and beryllium from the primordial hydrogen. Thus, GRB 090423’s afterglow properties indicate that the universe’s first stars must have formed less than 600 million years after the cosmic creation event.
In a different study, two astronomers at the University of Colorado employed the most current lists of the Milky Way Galaxy’s extremely metal poor stars in order to constrain the birth date of the last-formed population III stars.3 Not all metal-free stars form at the same time. The less massive ones will form later than the more massive.
The two astronomers showed that the metal content of the most metal-poor stars in the Milky Way Galaxy bear the signature of having formed from the gases ejected by the last-forming population III stars. Consequently, the researchers calculated the date for these last-forming population III stars to be about 13.4 billion years ago, or 335 million years after the cosmic creation event. As for the very massive first-forming population III stars, their birth date could be no earlier than about 200 million years after the beginning of the universe.
The dates calculated by the University of Colorado astronomers match well with predictions from the best big bang creation models. All of the chronometers discussed in this series bring to the table data that supports the creation event and the cosmos described in Scripture. Biblical cosmology continues to pass observational and theoretical tests and boosts confidence in the reliability in the Bible’s truth-claims.
|Part 1 | Part 2 | Part 3 | Part 4|
- Hugh Ross, The Creator and the Cosmos, 3rd ed. (Colorado Springs: NavPress, 2001), 23–29.
- Poonam Chandra et al., “Discovery of Radio Afterglow from the Most Distant Cosmic Explosion,” Astrophysical Journal Letters 712 (March 20, 2010): L31–L35.
- Michele Trenti and J. Michael Shull, “Extremely Metal-Poor Stars in the Milky Way: A Second Generation Formed after Reionization,” Astrophysical Journal 712 (March 20, 2010): 435–44.