Well, you might have to add another line to that address, as Laniakia, along with dozens of other nearby giant clusters, is all embedded within a great cosmic void stretching a billion light years from end-to-end. But if your sphere were smaller, you'd see you'd start to get different numbers in different locations. On the other hand, if you lived in an underdense region, your local neighborhood of space would gravitate less strongly than average, and the expansion rate would appear greater (higher) for you. With a radius of roughly one billion light years, the void containing our Milky Way, known as the KBC void (for scientists Keenan, Barger, and Cowie), is the largest confirmed void in the Universe. ESA/Herschel/SPIRE/HerMESIf there weren't a large cosmic void that our Milky Way resided in, this tension between different ways of measuring the Hubble expansion rate would pose a big problem.

Source: Forbes June 07, 2017 14:26 UTC