  A cosmology with a dynamical Planck mass $m_{pl}$ is shown to solve the
horizon and monopole problems (and possibly flatness) if there is an early MAD
(modified aging) era where the universe becomes older than in the standard
model as a result of a large $m_{pl}$: the causality condition is $m_{pl}(T_c)/
m_{pl}(T_o) \gta T_c/T_o$ ($T_c$ is some high temperature while $T_o = 2.74K$.)
Unlike inflation, there is no period of vacuum domination nor any entropy
violation. We study: a) bare scalar theories of gravity, b) self-interacting
models, and c) bare theories with a phase transition in the matter sector.
