In last week’s post, I explained how a team of astronomers comprehensively verified general relativity by achieving unprecedented accuracy in their gravitational field tests, even for extremely strong gravitational fields. I also discussed how this verification strengthens the case for a cosmic beginning and for a causal Agent beyond space and time who created our universe. In this post, I’ll show how additional measurements on our galaxy’s supermassive black hole help resolve discrepancies and lead to further compelling philosophical implications.
Cosmic Creation Implications
The now comprehensive verification of general relativity leaves little speculative room for physicists seeking an alternative to the God of the Bible to explain the existence of the universe. As I described in The Creator and the Cosmos, 4th edition, these physicists have been appealing to the quantum gravity era, when the universe was younger than 10-43 seconds, in their search for a possible alternative to the Creator.1 Some scientists speculate that during this extremely brief moment, quantum mechanics may have exerted an influence on the dynamics of the universe at least as strong as that of general relativity. They further speculate that quantum mechanics during the quantum gravity era may have operated in such a way as to, at least in part, invalidate the space-time theorems that imply a Causal Agent beyond space and time must have created the universe.
The 29-astronomer team’s measurements (see last week’s blog post) did not eliminate all these quantum gravity speculations, but they did rule out some. A fundamental principle of general relativity is what physicists term the Einstein equivalence principle. As the astronomers noted, “Violations of the equivalence principle are predicted by some theories of modified gravity motivated by the development of a quantum theory of gravitation.”2 They stated in their paper that what they discovered “constrains modified theories of gravitation that exhibit large non-perturbative effects around black holes.”3 In other words, some of the theoretical speculations designed to eliminate the need for a cosmic Creator have themselves been eliminated. Their paper provides yet another example of the biblical principle that the more we learn about the universe, the more evidence we will uncover for the handiwork of a supernatural, super-intelligent Creator. But there’s more.
Cosmic Expansion Rate Discrepancy?
The team’s new measurement of the distance to the center of our galaxy yielded a value that is 2.17% lower than the previous best determination. Unlike the previous measurements, the new measurement has a probable systematic error smaller than its probable random error. Hence, its value is more reliable.
The distance to the galactic center represents the foundational anchor for determining the expansion rate of the universe throughout the past few billion years, otherwise known as the Hubble Constant. A reduction of 2.17% in the galactic center distance translates into a 2.17% reduction in the value of the Hubble Constant.
As I mentioned in my blog posted on June 24, 2019, many people were captivated by a recent discrepant cosmic expansion rate measure4 by a team of astronomers led by Nobel laureate Adam Riess. There, they inferred that the ΛCDM (universe dominated first by dark energy and then by cold dark matter) big bang creation model either was in trouble or in need of a major adjustment. The discrepant measurement was 9% higher than the Planck satellite measurement5 of the early universe’s cosmic expansion rate. The new distance to the galactic center, however, reduces the discrepancy to a little below 7%.
Other Star Measurements Help Eliminate the Discrepancy
Recently, instead of using Cepheid variable stars to determine the present universe’s cosmic expansion rate, a team of ten astronomers led by former graduate classmates of mine, Wendy Freedman and Barry Madore, used “tip of the red giant branch stars.”6 In this technique, the luminosity of the brightest red giant branch stars (see figure) in a galaxy is used to determine the distance to that galaxy.
Figure: Red Giant Branch Stars in the Globular Cluster M5
In this color-magnitude diagram for the stars in M5 the red colored stars are red giant branch stars. In all star clusters and galaxies the brightest red giant branch stars are “standard candles.” That is, these brightest red giant branch stars all possess the same intrinsic brightness and, thus, can be used to accurately determine the distance to their host’s star clusters and galaxies.
image credit: Lithopsian, Creative Commons Attribution
Instead of a 9% discrepancy with the Planck Satellite measurement, their measurement was larger by only 3.6%. Subtract another 2.17% due to the new measurement of the distance to the galactic center, and the Freedman-Madore team’s measurement is discrepant by only 1.4%—well within the probable random errors on both the Planck satellite and the tip of the red giant branch star measurements.
It is also worth noting that the tip of the red giant branch measurement of the present universe’s cosmic expansion rate of 69.8±0.8 (random)±1.7 (systematic) agrees remarkably well with the nine-year WMAP satellite determination of the early universe’s cosmic expansion rate of 69.32±0.80 kilometers/second/megaparsec.7 The agreement is especially remarkable when one notes that in a universe dominated by dark energy and dark matter—where both are governed by single constants of physics—the universe is predicted to expand about 1% more slowly during its infancy than during its present era. In other words, the ΛCDM big bang creation model is better affirmed than ever before.
Implications of a “Tiny” Supermassive Black Hole
I’ll close by offering one more implication from the large team of astronomers’ efforts. Three months ago I wrote two blogs (here and here) on supermassive black holes. All galaxies possess a supermassive black hole in their central core and, with one known exception, the bigger the galaxy the bigger the supermassive black hole. That one exception is our own Milky Way Galaxy. It possesses a supermassive black hole at least twenty times smaller than what its physical size and properties would dictate.
If our galaxy’s supermassive black hole were any bigger, advanced life would not be possible in our galaxy. The radiation emitted from just outside the supermassive black hole’s event horizon would kill any beings like us. The good news for us is that the new measurement by the team of 29 astronomers establishes that our galaxy’s supermassive black hole is slightly smaller than we previously thought. That is, our galaxy appears to be even more amazingly designed for our benefit.
All the new astronomical discoveries I’ve reported here in the last two weeks affirm biblical statements in Job and Psalms about the realm of nature, including the descriptions that God “stretches out the heavens.” Once again, tested science shows that the more we learn about our universe, galaxy, and planet, the more reasons we accumulate to believe in Christ as our Creator, Lord, and Savior.
Featured image credit: Planck Collaboration