  Dark matter appears in two forms as a consequence of the fluid mechanics of
self-gravitational condensation. Condensation occurs primarily on non-acoustic
nuclei rather than on the acoustic nuclei of the Jeans (1902) criterion,
leading to a very different scenario for structure formation. Viscous forces at
10^12 s (30,000 y) after the big bang permit decelerations of 10^47 kg
protosupercluster plasma masses, and 10^42 kg protogalaxy masses at 10^13 s
(300,000 y). Then gas formed, and all the baryonic universe became a
"primordial fog" of 10^23 kg particles at the viscous Schwarz scale: 100% dark
matter. Some of these H-He objects have collected to form stars, but most
persist as dark dwarfs in galaxy halos. They manifest themselves in quasar
microlensing observations as "rogue planets", Schild (1996), "dark galaxies",
Hawkins (1996), and as comets "brought out of cold storage", O'Dell and Handron
(1996). Non-baryonic WIMP fluids are superviscous, with large viscous Schwarz
scales, and condense slowly to form most of the dark matter of galaxy
superclusterhalos and clusterhalos.
