The DESI collaboration has found that the acceleration of the universe’s expansion weakens with time, and JWST has found a large population of galaxies with z > 10. The Friedmann coordinates of the Robertson-Walker metric imply a Big Bang birth of the universe with unbounded expansion speed and perpetual gravitational deceleration of that expansion. The 1998 discovery that the universe’s expansion instead accelerates led to trying a cosmological constant in the Einstein equation, but this doesn’t accommodate the acceleration’s weakening with time found by DESI. Also, the large population of galaxies with z > 10 doesn’t jibe with the universe’s unbounded initial expansion speed. Einstein’s observationally-tested 1915 coordinate condition, however, is Lorentz covariant, which bounds all speeds by c. It also implies refractive gravitational slowing of incoming light, so outgoing light is accelerated. Outgoing galaxies whose z > 0.94 are similarly accelerated, so the universe’s expansion is accelerated, a gravitational effect that inherently weakens as the universe expands. We illustrate the above effects by plotting the time evolution of the simplest expanding-dust-sphere model universe in both Friedmann and Einstein coordinates.