Classical unified field theories version of the general-relativistic field equation expressed the property that the universe was "self-gauging". Since the simplest cosmological model (the De Sitter universe) that solves that equation is a spherically symmetric, stationary, closed universe (exhibiting a cosmological red shift, which is more conventionally interpreted as due to expansion), it seemed to explain the overall form of the universe. Like many other classical unified field theorists, Eddington considered that in the Einstein field equations for general relativity the stress–energy tensor formula_1, which represents matter/energy, was merely provisional, and that in a truly unified theory the source term would automatically arise as
Unified growth theory take-off from an epoch of stagnation to the modern era of sustained growth. The testable predictions of this evolutionary theory and its underlying mechanisms have been confirmed empirically and quantitatively. Unified growth theory contributes to Macrohistory. It sheds light on the divergence in income per capita across the globe during the past two centuries. It identifies the factors that have governed the transition from stagnation to growth and have thus contributed to the observed worldwide differences in economic development. It highlights the persistent effects that variations in historical and prehistorical conditions have had on the composition of human capital and