During my graduate school days, when evidence for a big bang universe was growing exponentially, “mixmaster” models for the universe gained popularity as a potential escape, a loophole for those wanting to ignore the implications of a cosmic beginning in the recent past (as in a few billion or tens of billions of years ago). At that time, such models seemed the best, if not the only, way to explain how the universe came to be so homogeneous (all component parts having the same composition and structure) and isotropic (all points in space manifesting the same physical properties and same physical history).
These mixmaster models, as you may have guessed, took their name from the Sunbeam Mixmaster of that era, used by homemakers to blend and beat cake ingredients, among other things. Just as the rotation of the beaters can blend different substances, dry and liquid, into a smooth, homogenous whole, so, too, the continuous vigorous rotation of the universe could explain the observed homogeneity and isotropic characteristics of the universe. Some mixmaster models propose that parts of the universe are expanding while others are contracting, all this in such a manner that the universe would mix forever without a beginning or a Beginner.1
Because every body within the universe—whether a moon, planet, star, galaxy, or galaxy cluster—rotates, the idea of cosmic rotation seemed a natural and reasonable conclusion. No alternative seemed plausible until Alan Guth and Alexei Starobinski simultaneously and independently proposed their “inflationary” model.2
The inflationary big bang scenario says that in the early moment of cosmic history when the strong-electroweak force split apart into the strong nuclear force and the electroweak force (at about 10-34 seconds after the cosmic origin event), the entire universe briefly experienced hyper-rapid expansion. This model indicates that between 10-35 and 10-32 seconds after the cosmic beginning, the universe expanded by more than a factor of 1030. To put it another way, in about a billionth of a trillionth of a trillionth of a second, the universe expanded from being about a hundred millionth of a trillionth the diameter of a proton to being about the size of a grapefruit.
This early and extremely brief hyper-rapid expansion (far faster than the velocity of light) would explain how the universe we observe today can be “thermally connected” in its entirety—meaning thermal conditions in any part are affected by thermal conditions in any and all other parts, with no parts unaffected. Such complete thermal (or causal) connection solves the puzzle of how the universe retained its primordial homogeneous and isotropic state without cosmic rotation.
In fact, the inflationary big bang model cannot even tolerate any measureable cosmic rotation. Any cosmic rotation that existed prior to the inflationary episode would be shrunk to unobservable levels as a result of inflation.
Herein lies a dramatic and definitive scientific test of competing theological perspectives. If astronomical measurements were to demonstrate that the universe indeed rotates in mixmaster fashion, then the big bang features described in the Bible could be explained away. Key biblical doctrines would be falsified. If, on the other hand, astronomical measurements either negate or show severe limits on cosmic rotation, the mixmaster models would be ruled out. And this one proposed escape hatch from the biblical account of cosmic origins would be closed.
Clearly, a lot is riding on whether or not the universe rotates.
For decades scientists presumed that to measure the universe’s rotation would be impossible. After all, measuring the rotation rate of planets, stars, galaxies, and galaxy clusters requires that the observer view the object from outside. (The astronomer can measure the motion of the object in or on which he/she resides only relative to that of some outside body or bodies.) But in the case of the universe itself, there is no “outside” perspective for the researcher.
Eventually, however, astronomers figured out two possible ways to detect cosmic rotation and its rate. The first is made possible by the fact that the cosmic background radiation is slightly hotter on one side of the sky than on the opposite side. This dipole structure—a result of our galaxy’s being pulled toward the Virgo Cluster of galaxies, which in turn is pulled to a super cluster of galaxies called the Great Attractor, which in turn is pulled to a super-super cluster of galaxies called the Monster Attractor—will show measurable torque or twisting if the universe had rotated, even very slowly, at the time this radiation was emitted (when the universe was a miniscule fraction of its currently measured age).
A team of British and Polish astronomers applied this method and came up with a range of upper limits on cosmic rotation at that very early age. It’s a wide range because of uncertainties about the geometry of the universe, but revealing nonetheless: anywhere from one complete turn in 60,000 years (if the universe manifests an open geometry) to once every 10,000,000,000,000 years (if the universe manifests a closed geometry).3 According to the conservation of angular momentum (familiar from seeing how ice skaters slow down their spin), such rates would be about a billion times slower today because of cosmic expansion since that early era. In other words, whatever the geometry, these rates measure too slow to earn the mixmaster name.
More recently, two Chinese astronomers used a different method, called the Sachs-Wolfe effect, to determine the limits on cosmic rotation.4 Armed with the latest results from the WMAP satellite’s measurements of the cosmic background radiation, their research shows that when the universe was 380,000 years old (when the background radiation was emitted) it was rotating no faster than one 360° turn every 6,000,000,000 years regardless of cosmic geometry.
This stringent limit deals a knockout blow to cosmic mixmaster models. And in doing so, it more firmly establishes inflationary big bang models, which happen to be fully consistent with biblical cosmology. Once again scientific advance affirms what Scripture has said for thousands of years.5