  Self-similar Euler singularities may be useful for understanding some aspects
of Navier-Stokes turbulence. Here, a causal explanation for intermittency is
given, based on the control of the sudden growth of the gradients by the Euler
equations. This explanation uses certain Euler solutions as intermediate
asymptotics in Navier-Stokes turbulence \cite{barenblatt} -- controlling the
dynamics over a limited spatial and temporal domain. These arise from an
analysis of similarity equations, previously discussed by Pelz and Green
\cite{pelz}, which yield experimentally testable predictions. Three main points
are presented here: scalings of suitable characteristic lengths with time from
a critical time $l \sim (t_\circ -t)^\alpha$, $\alpha>1$, a discussion of
invariant sets of the similarity equations that result, and a discussion of
cutoff mechanisms. The value $\alpha = 3/2$ appears to correspond to Kolmogorov
scaling for turbulence. Some limited experimental evidence is presented from
Eulerian gradient measurements at the Kolmogorov scale showing $1<\alpha<3$
values. Much testing is necessary to ascertain the final usefulness and
validity of these ideas, as several conceptual obstacles remain.
