Relative to what? That makes no sense.
Relative to the Cosmic Microwave Background. Seems to be the closest thing to an absolute reference frame.
The cosmic microwave background has no center, any claims that it even has a direction is controversial.
Is it controversial? I thought it was pretty established. In Wikipedia it says:
From the CMB data, it is seen that the Sun appears to be moving at 369.82±0.11 km/s relative to the reference frame of the CMB (also called the CMB rest frame, or the frame of reference in which there is no motion through the CMB). The Local Group — the galaxy group that includes our own Milky Way galaxy — appears to be moving at 620±15 km/s in the direction of galactic longitude ℓ = 271.9°±2°, b = 30°±3°.[88] The dipole is now used to calibrate mapping studies.
They go coast to coast?
This actually explains a lot.
Is the reference frame the CMB? You’d think you could just choose the reference frame at that point and move however you want, but arguing the physics of hypothetical metaphysical beings probably doesn’t make much sense.
That explains why there are no ghosts.
