Lookback Time Equation

There is only the observable Universe.

The Universe is closed, positively curved and asymptotically flat.

The Universe is expanding at exactly the velocity of light.

This explains cosmic isotropic as 'c' has always been the same.

Consider the circumference of a circle that represents a universe at age UAge.

For an object with redshift z it's Lookback Time is now EA.

Dilation = UAge and Dilation = z + 1 (UAge- d)

UAge = z + 1 EA

EA = UAge z + 1