  We model the spectral energy distributions (SEDs) of 23 protoplanetary disks
in the Taurus-Auriga star-forming region using detailed disk models and a
Bayesian approach. This is made possible by combining these models with
artificial neural networks to drastically speed up their performance. Such a
setup allows us to confront $\alpha$-disk models with observations while
accounting for several uncertainties and degeneracies. Our results yield high
viscosities and accretion rates for many sources, which is not consistent with
recent measurements of low turbulence levels in disks. This inconsistency could
imply that viscosity is not the main mechanism for angular momentum transport
in disks, and that alternatives such as disk winds play an important role in
this process. We also find that our SED-derived disk masses are systematically
higher than those obtained solely from (sub)mm fluxes, suggesting that part of
the disk emission could still be optically thick at (sub)mm wavelengths. This
effect is particularly relevant for disk population studies and alleviates
previous observational tensions between the masses of protoplanetary disks and
exoplanetary systems.
