In the context of special relativity, the universe does not have a single, universal rest frame. All motion is relative, and there is no absolute frame of reference. An object may be at rest relative to one observer, but in motion relative to another observer.

In a broader sense, the universe as a whole does not have a rest frame because it is constantly expanding. There is no point in the universe that can be considered stationary relative to everything else. All galaxies and stars are moving away from each other, and the universe itself is expanding at an accelerated rate.

It's important to note that the expansion of the universe does not violate the principle of relativity. The expansion is not happening in any particular direction; rather, all points in the universe are moving away from each other. This means that there is no way to define a single rest frame for the entire universe.