Talk:Weyl's postulate/to do

tasks for expert:

• write and link to articles on ADM formalism,
• explain hyperslices and evolving geometry therein,
• write and link to articles giving explicit examples of congruences with zero and nonzero vorticity in flat and curved spacetimes,
• explain therein the relation to locally non-rotating and to fluid dynamics,
• write articles on Bianchi dusts, Wainwright solutions, etc.