In an older question from June 2011, Why does each celestial object spin on its own axis?, apparently revived by the system, a user is asking about the origin of the rotation of celestial bodies.
The accepted answer (with 17 votes) states the following:
When things collapse under their own gravity in space (i.e. clouds of gas and dust), any small amount of asymmetry in the collapse will be enough start it spinning.
And then it goes on saying:
Even if it spins by a tiny amount, as it collapses, angular momentum conservation will mean it spins more and more quickly.
Is all this really correct?
I could try to ask in a comment to the answer. I actually did. But the author is no longer registered.
Hence I am asking it as a question.
But that is not the end of the story. As I was about to ask my question, I looked for other relevant questions, and there are some. I did not make an exaustive survey, but I did not find one that had satisfactory answers:
On the origin of the rotation of celestial bodies (december 2011) has just one accepted answer (0 votes) stating essentially that the solar system has angular momentum because it started from a cloud that had angular momentum. No comment.
Why does everything spin? (july 2011) is questionning about everything from galaxies to electrons. The answers are of a much higher quality, but while they seem to justify the possiblility of spin and angular momentum (and its conservation), there are not clear on how it appears, at least for celestial bodies.
Origin of motion and relative speed of bodies in the universe (june 2013): That was my own very naive first question on this site. It is related but does not directly address spin.
One answer I found is that momentum appear from bodies in relative motion past each other. Nice, but not really an answer: where did they get their relative speed to begin with. Unfortunately the answer is: from the angular momentum of larger structures they belong to (well, it can be more comples). So this is just chicken and egg explanation. But how did it get started?
Note that my question is not a duplicate, since it is primarily whether the above statements are correct, which is not considered in these other questions.
Furthermore, these questions are fairly old, and given that none had received answers that seem to answer the question of the origine of existence of celestial angular momentum (not in a way I can understand anyway), it may be appropriate to attempt restarting the process, with the above discussion to motivate that an answer should explain the physical mechanism that started the existence of spin of celestial bodies.