This article takes a different approach, based on Noether’s theorem on energy conservation and the comoving coordinates of Robertson and Walker.
The age now results in 11 billion years and, surprisingly, remains the same for future observers!
To explain this, Robertson and Walker had a brilliant idea in 1936: comoving coordinates, which abides NASA’s found fast, far away stars formation and the Pioneer 10&11 deceleration.
As a consequence, Einstein’s cosmological model is changed: the fourth dimension is now based on time: the universe expands in time and the Big bang lies on the Hubble horizon.
We live surrounded by space but on the edge of time.
Einstein would be pleased!