About the meaning of Einstein equation
I found this
http://www.settheory.net/cosmology
http://www.settheory.net/general-relativity
This is better than the John baez ' article
The relation between energy and curvature is not only expressed but also justified
It is directly applied to an important example (universal expansion)
The expression is simpler (relating 1 componnt of the energy tensor to 3 components of the Riemann tensor)
Both diagonal space and time components of the relation are expressed and justified, resulting in showing their similarity like a coincidence
.......
