A spinning universe isn’t the only universe

To understand why a rotating universe implies more than one universe, Poplawski refers to “frames of reference.” These are sets of coordinate systems that are integral to physics, which allow motion and rest to be measured.

Imagine two scientists, Terra and Stella. Each is in their own frame of reference, but Terra on Earth, Stella in a spacecraft traveling past our planet. Terra sees Stella’s frame of reference (the spacecraft) moving in relation to her own (the Earth), which is at rest. Stella, meanwhile, sees her frame of reference at rest while it is Terra’s frame of reference in motion as the Earth races away.

Poplawski pointed out that if the universe is rotating, then its frame of reference is rotating, and that only makes sense if it is rotating in relation to at least one other frame of reference.

“If the universe is rotating, it must rotate relative to some frame of reference corresponding to something bigger,” he continued. “Therefore, the universe is not the only one; it is a part of a multiverse.”