In this short survey paper, we shall discuss certain recent results in clas
sical gravity. Our main attention will be restricted to two topics in which
we have been involved; the positive mass conjecture and its extensions to
the case with horizons, including the Penrose conjecture (Part I), and the
interaction of gravity with other force fields and quantum-mechanical parti
cles (Part II). (C) 2000 American Institute of Physics. [S0022-2488(00)0060
6-X].