Important decisions in life—who to marry, which job to take, what house to buy—are best made in the context of multiple independent confirmations. When every possible confirming source says this is the right choice, you can be confident you have made the right decision.
The same principle applies in scientific research. Scientists strive to test their theories by developing as many independent experiments and observations as possible. Given an adequate number of these independent tests, if every possible experimental and observational method produces results consistent with a particular theory, then scientists can be reasonably assured the theory is correct. And when some of the confirming results are based on experiments and/or observations free of assumptions, then scientists rightly judge the theory as proven beyond all reasonable doubt.
This kind of hard scientific proof is especially important in helping people change their philosophical and theological beliefs. Such is the case with the biblical big bang creation model.1
Continual cosmic expansion under fixed physical laws from an actual beginning of matter, energy, space, and time represents the heart and soul of the biblical cosmic creation model. For over two thousand years the Bible stood alone as the only text making such claims about the universe.2 Not until Albert Einstein produced his theory of general relativity in 1916 did scientists even consider the possibility of continual cosmic expansion. Thus, efforts to further confirm continual cosmic expansion scenario not only establish the validity of the biblical cosmic creation model, they also demonstrate the Bible’s capacity to accurately predict future scientific discoveries. In addition, increasingly reliable measurements of the rate of cosmic expansion and of its relative constancy can rigorously test the dispute between old- and young-universe creationism.3
Until just a decade ago, the only accurate methods for determining the expansion rate of the universe relied on the distance ladder method. Even today, researchers consider this method one of the pillars for calculating the cosmic expansion rate because it offers insights into the expansion rate at a wide variety of different epochs throughout the history of the universe.
The distance ladder method uses direct distance measurements on nearby objects to calibrate indirect methods for far away objects. Direct cosmic distance measurements are based on plane geometry theorems. For example, if one knows the length of the base of an isosceles triangle, then measurements of the angles at either end of the base will deliver the distance to the vertex of the triangle. The diameter of Earth’s orbit about the Sun (about 185,912,076 miles or 299,195,741 kilometers) has been the traditional base of the triangle in determining distances to nearby stars. Astronomically speaking, however, this base is so tiny that the accuracy of measurements to even the nearest stars is no better than a few percent. This particular direct distance measuring method delivers accurate calculations only for stars located up to a little more than a thousand light-years away.
Herein lies the rub. To gain any measurement of the universe’s history, astronomers must use their limited direct distance measurements to calibrate indirect methods for far away objects. The indirect methods make certain assumptions about the properties of the observed objects. Only the direct methods are assumption free. Clearly, there is a need in astronomy to improve the accuracy and reach of direct methods. The cosmological ideal would be to measure the cosmic expansion rate using only accurate direct distance calculations.
Thanks to new measurements on galaxies both near and far, that ideal has now been achieved. Measurements of the expanding shock fronts of supernova eruptions provide direct distance values for galaxies within 20 million light-years. Meanwhile, observations of water maser sources orbiting about the center of the host galaxy yield accurate determinations for galaxies within 200 million light-years. And measured time delays of gravitational lenses give precise values for galaxies up to several billion light-years away. The combination of these three techniques gives astronomers the best unambiguous means for proving that we indeed live in a universe that has continually expanded from the cosmic creation event. It also allows them to determine the nature of dark energy (the dominant component of the universe), the geometry of the universe (a test of multiverse hypotheses), and the age of the universe (a test of young-earth creationism).
Parts 2 and 3 of this articles series will briefly describe how these three techniques work and explain the latest results achieved through them. Part 4 will explore the cosmological conclusions astronomers can draw from these achievements.
Named for the Roman god of war, our red-tinged planetary neighbor continually draws our fascination. In fiction, Mars is often the source of malevolent...
As scientists better understand astrophysical sources of fluorine, the case for fine-tuning in the formation of the solar system grows stronger. Fluorine is...
