Expansion of the universe.

<p>The expansion of the universe is the increase in distance between any two given gravitationally unbound parts of the observable universe with time. It is an intrinsic expansion whereby the scale of space itself changes. An extra dose of dark energy in the early universe, dubbed early dark energy, could reconcile the conflicting values of the Hubble constant. The outward pressure of this early dark energy would have sped up the universe’s expansion.</p>