Multiverse Musings – Signatures from Beyond the Universe
Next August, Reasons To Believe will host a conference on a week-long Alaska cruise onboard a Holland America ship. Those of you who plan to come along will enjoy all the comforts the ship offers as it sails along the beautiful Alaskan coast. With everything bearing the Holland America logo, imagine finding each room stocked with Royal Caribbean sheets and towels. Such evidence would indicate that other vessels beyond our own existed.
A team of cosmologists recently made a similarly shocking discovery when looking at our universe.
Since its detection in the 1960s, the cosmic microwave background (CMB) radiation has provided a wealth of information about our universe. This uniform, pervasive radiation points to a cosmic beginning to all of space and time. More recent studies of the CMB demonstrate that our observable universe exhibits a flat geometry and is dominated by a mysterious “dark energy.”
Perhaps the most remarkable discovery to come from studies of the CMB is that the observable universe appears to be moving in a particular direction!
The gravitational potential of galaxy clusters and their motion affected CMB photons as they passed through the clusters on their way to Earth; scientists refer to this as the Sunyaev-Zel’dovich (SZ) effect. By measuring the SZ effect caused by the clusters’ motions—the kinematic SZ (or KSZ) effect—scientists can determine the direction and speed of the clusters. Although for individual clusters the KSZ is generally small and indistinguishable from noise, any coherent motion becomes detectable when analyzing a large number of galaxy clusters.
As reported in a recent article in the Astrophysical Journal, a team of scientists performed such an analysis. They’ve found that the entire sample of galaxy clusters is moving in the same direction with the same speed out to distances of six billion light-years. The most straightforward interpretation of this result is that gravitational effects occurring before inflation pulled the observable universe in one direction. Although inflation moved the mass/energy responsible for this “tug” far beyond our ability to detect it directly, the observable universe continues to move in the direction it was tugged.
If this result stands under further testing, it would add to the observational evidence that we live in a Level I multiverse. The authors of the article also note that this explanation may also account for the unexpectedly small values measured at the lower harmonics in the CMB radiation compared to predictions. As I described in a previous TNRTB, some have used this discrepancy to argue that the universe is basically the same size as the observable universe (which means no Level I multiverse).
To borrow an analogy from my colleague Kenneth Samples, many think multiverse furniture fits more comfortably in naturalists’ worldview. I have argued to the contrary. Not only does the multiverse not help naturalists, it finds a welcome home in a Christian setting.
If you would like to see a question about the multiverse addressed in this forum, send it to [email protected].