Not until Albert Einstein produced his theory of general relativity in 1916 did scientists even consider the possibility that the cosmos continually expands. And yet five ancient writers—Job, David, Isaiah, Jeremiah, and Zechariah—all described this expansion more than two thousand years ago.1 For centuries the Bible stood alone as the only text making such a claim about the universe. So today, as the body of evidence for continual expansion grows, the case for the reliability and predictive power of the Bible and of the Christian worldview also grows. A breakthrough from a team of American radio astronomers just added to it.
Until a few years ago, the most reliable measurements of the expansion rate of the universe relied on what’s called the “distance-ladder” method. (Even today, this method is still considered one of the pillars for determining the expansion history of the universe because it offers insights to the expansion rate at multiple cosmic epochs.) Using direct distance measurements to nearby objects, astronomers use indirect distance methods to extrapolate the distance to more-distant objects. The indirect methods make certain assumptions about the properties of the observed objects while the direct methods are assumption free.
Direct distance measurements rely upon the theorems taught in high school-level geometry classes. Traditionally, the diameter of Earth's orbit becomes the base of the triangle for these calculations. But because that base of 186 million miles is comparatively small (on an astronomical scale), the nearly perpendicular side angles and extremely narrow vertex angle of the triangle—think of a very long, narrow triangle—for stars located more than a thousand light-years distant seriously limit the precision of such measurements and thus the applicability of the method.
In recent months, however, an American radio astronomy team announced the completion of a three-year research project that vaulted measuring accuracy from distances of about a thousand light-years or less to a distance of 25 million light-years. With the help of NGC 4258 (a galaxy), they improved the accuracy by a factor of 25,000.2 Rather than using the diameter of Earth's orbit as the baseline of the distance-calculating triangle, they used the much larger baseline provided by a microwave laser, or “maser,” centered on a super-giant black hole in NGC 4258.
Because the astronomers are making use of radio wavelengths, they are able to electronically link radio telescopes all over the globe to create an instrument with an angular resolving power a thousand times greater than the biggest ground-based optical telescope in existence and a hundred times superior to the Hubble Space Telescope. The long-term integration over which observations of the maser are made allows for an additional hundredfold improvement in the accuracy of the measurements.
As a result of this project, the radio astronomy team has now accumulated the data to produce a direct distance measurement from Earth out to NGC 4258, one that’s accurate to about 5 percent precision (and to about 3 percent in subsequent observations). This accuracy more than doubles that of even the best among various indirect methods, regardless of the reliability of the assumptions on which they rest. Such accuracy will permit some important advances, including these two: (1) it will allow astronomers to test the validity of multiple assumptions underlying the indirect measuring methods; and (2) it will deliver double the quality and, therefore, twice the reliability of many of researchers’ earlier cosmic expansion measurements.
So far, the team has published their observations of the maser, their data reduction techniques, and the temporal and spatial characteristics of the maser. In a soon-to-be-published paper they will present their actual measurements of the distance to NGC 4258. Then we can all enjoy a more certain picture of the universe's expansion history and a more accurate calculation of the time back to the cosmic creation event—the event of which Moses wrote in Genesis 1:1.
- Hugh Ross, The Creator and the Cosmos, 3rd ed. (Colorado Springs: NavPress, 2001): 23-29.
- A. L. Argon et al., “Toward a New Geometric Distance to the Active Galaxy NGC 4258. I. VLBI Monitoring of Water Maser Emission,” Astrophysical Journal 659 (April 20, 2007): 1040-62.