  Applying constant tensile stress to a piece of amorphous solid results in a
slow extension, followed by an eventual rapid mechanical collapse. This "creep"
process is of paramount engineering concern, and as such was the subject of
study in a variety of materials, for more than a century. Predictive theories
for $\tau_w$, the expected time of collapse, are lacking, mainly due to its
dependence on a bewildering variety of parameters, including temperature,
system size, tensile force, but also the detailed microscopic interactions
between constituents. The complex dependence of the collapse time on all the
parameters is discussed below, using simulations of strip of amorphous
material. Different scenarios are observed for ductile and brittle materials,
resulting in serious difficulties in creating an all-encompassing theory that
could offer safety measures for given conditions. A central aim of this paper
is to employ scaling concepts, to achieve data collapse for the probability
distribution function (pdf) of $\ln{\tau_w}$. The scaling ideas result in a
universal function which provides a prediction of the pdf of $\ln{\tau_w}$ for
out-of-sample systems, from measurements at other values of these parameters.
The predictive power of the scaling theory is demonstrated for both ductile and
brittle systems. Finally, we present a derivation of universal scaling function
for brittle materials. The ductile case appears to be due to a plastic necking
instability and is left for future research.
