:To get to the actual Q, the cloud likely has a tiny rotation inherited from larger galactic rotation, which in turn comes from galactic cluster eddies, ultimately going back to the Big Bang ( although what caused the initial rotation right after the Big Bang is a mystery ).
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Yet human interstellar expansion at average speeds of even 0.1 % of " c " would permit settlement of the entire Galaxy in less than one half of a galactic rotation period of ~ 250, 000, 000 years, which is comparable to the timescale of other galactic processes.
