Gravity and how it starts and stops

[Eric pelland]

Yes. What wasn't blown away formed into a protoplanetary disc, which coalesced into the current solar system bodies we see today - about 0.2% of the Sun's mass.

Yes I agree

 

[DaveC426913]

The energy to blow away comes from friction.

No.

 

[sophiecentaur]

Does not Angular Momentum have a large part to play in determining what mass the star can have? A spinning protostar can only stay together if the mass is high enough to contain itself at a given rotation rate, The excess angular momentum is, as I remember, divided up between what will end up as the contents of the planetary disc.
This link gives a list of the orbital angular momentum of the Solar System objects and also the rotational Angular momentum of the Sun. The majority of the original angular momentum ( assuming it hasn't gained significant mass) was apportioned this way because the angular velocity of the Sun limited its possible mass. The surplus 0.1% of the original mass went into orbit.
If the original gas cloud had been much more massive, I suggest that the Sun would have still ended up with the same mass and the total angular momentum would have needed to be less for a larger star to have formed.

 

[Ian J Miller]

As an aside, I do not believe anyone knows how stars start accreting. The difficulty is that the gas has to radiate energy as it accretes, but hydrogen and helium are not good at this when tolerably cool (say, up to 2,000 K). Now they radiate through collisions with dust, but originally, no dust. So basically, while the gas moves around in the cloud, it is very difficult to get specific accretion going. It may make small clumps, but these dissipate. Some think initial accretion starts due to a compression wave, such as a nearby supernova, and it starts very well during and immediately after galactic collisions, but the evidence seems to be that gravity alone will not start it.

 

[Droidriven]

Where does gravity start and stop? Gravityf

Do you mean to say...

Why does matter localize and gravitate "here" and not "there"?

Please correct me wherever I am wrong or could be more specific here, but..

Chaos? Entropy in a complex system? The so-called "butterfly effect"? The randomness of complex systems demonstrated by the double pendulum? Are any of these relevant, if so, how? If not, why?

Somehow, at Big Bang, in a way that is unexplainable/immeasurable(determinism vs randomness), the initial conditions of the universe(its matter/energy distribution) determined the "pattern" of distribution of matter that led to the distribution that is observed. Expansion, localization and gravity took over from there, still following the "pattern" of initial distribution and the laws of thermodynamics/physics. The fluctuations observed in the CMB are said to be the fingerprint of that initial distribution of matter. Is that anything close, guys?

I don't post much and I'm far from well versed, but willing to question. Hopefully, relevant questions.

 

[rootone]

It is thought that for a very brief amount of time, right after the initial big bang event,
the four forces in nature which we see today including gravity, would have been unified, as one super-force.
Everything happening to that field at the time would be subject to quantum fluctuations.
When gravity becomes separate, the gravitational field retains some of the granularity (quantum artifacts) present in the original superforce field.