**3. Conclusions**

We started from the undisputable fact that, from various astrophysical observations of very different kinds, our universe has a preferred direction in space. We proposed a configuration where two three-dimensional universes (one of which is ours) are embedded in a four-dimensional space and rotate about their barycenter in such a way that the centrifugal force nearly (but not exactly) cancels out their mutual gravitational pull. This would explain not only the existence of a preferred direction within each of the threedimensional universes (the direction to the other universe), but also the fact that the bulk flow velocity, observed in our universe, is relatively small.

We pointed out that this configuration could also explain the perplexing features of the UAP recorded by various detection systems—the features presented in the latest official report by the US Office of the Director of National Intelligence. Thus, the proposed configuration of the two rotating, parallel, three-dimensional universes seems to explain both the variety of the astrophysical observation and (perhaps) the observed features of the UAP.

We mention that one of the interpretations of quantum mechanics suggests the existence of parallel universes. It is the many-world interpretation, proposed as early as 1957 [19].

The totality of the astrophysical observations should be emphasized—those proving the existence of the preferred direction in our universe, as well as astrophysical observations where a weak but non-zero bulk flow (i.e., the gravitational pull from the "outside") was measured. This seems by itself to be sufficient for making the proposed configuration of the two rotating, parallel, three-dimensional universes viable. We hope that our work stimulates a further discussion of these issues.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** All data is included in the paper.

**Conflicts of Interest:** The author declares no conflict of interest.
