On Thu, 03 Jan 2019 09:43:14 +0100, Paul Schlyter
wrote:

On Wed, 02 Jan 2019 15:16:41 -0700, Chris L Peterson
wrote:
The diameter of the 4D sphere whose surface we're on is 13.8 billion
years. The diameter of the 3D sphere that defines the observable
universe (a section of the surface of the 4D sphere) is about 93
billion light years, which reflects its increase in size over 13.8
billion light travel years.

Then it has expanded at (90-13.8)/13.8 times the light speed.

Nothing constrains the speed of expansion of the Universe. Indeed, the
edge of the observable universe is simply defined by the distance
beyond which the expansion relative to our position is greater than c.
Every point in the Universe has its own observable universe.