  Black holes can be practically located (e.g. in numerical simulations) by
trapping horizons, hypersurfaces foliated by marginal surfaces, and one desires
physically sound measures of their mass and angular momentum. A generically
unique angular momentum can be obtained from the Komar integral by demanding
that it satisfy a simple conservation law. With the irreducible (Hawking) mass
as the measure of energy, the conservation laws of energy and angular momentum
take a similar form, expressing the rate of change of mass and angular momentum
of a black hole in terms of fluxes of energy and angular momentum, obtained
from the matter energy tensor and an effective energy tensor for gravitational
radiation. Adding charge conservation for generality, one can use Kerr-Newman
formulas to define combined energy, surface gravity, angular speed and electric
potential, and derive a dynamical version of the so-called "first law" for
black holes. A generalization of the "zeroth law" to local equilibrium follows.
Combined with an existing version of the "second law", all the key quantities
and laws of the classical paradigm for black holes (in terms of Killing or
event horizons) have now been formulated coherently in a general dynamical
paradigm in terms of trapping horizons.
