Star formation:
https://en.wikipedia.org/wiki/Star#Star_formation
So, the newly formed stars "emit jets of gas". Why would they do that? I thought gravity pulls the gas in - to the center. Also they should make up their mind - do stars emit jets or do black holes emit jets? Or maybe it's the quasars:
https://phys.org/news/2014-11-spooky-al ... years.html
Besides that, my question is: how do they model gravity for a gas cloud? Each atom is pulled towards the center of mass? With a force equal to the total gravity the entire gas cloud mass can create? There is something wrong here. An atom in a sphere, halfway between the surface and the center, would be pulled towards the center with less force than an atom on the surface, because that atom on the surface has all the mass on one side. The atom at half the radius has some mass on one side, and some mass on the other.
Is this reasoning correct?
If it is, then it's another problem for those that want to have gas clouds collapse on themselves just because of gravity, then explode into stars, then keep a spherical form quite constant for billions of years of explosion...
(replaced "molecule" with "atom" because this is about hydrogen clouds)
And another question: Why is there magma inside the Earth?
Is it because of the meteorites that formed the Earth just smashed into each other at high speed? Even if they can't replicate the formation of a planet with a computer model now.
Point sources of gravity
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Re: Point sources of gravity
I was also having problem when I was examining the gravitational field within the sun, the small g field. First we know all planets and our sun are spheres. I think it has to do with minimal potential energy of the object - similar to spherical water droplets.Roshi wrote:Star formation:
https://en.wikipedia.org/wiki/Star#Star_formation
So, the newly formed stars "emit jets of gas". Why would they do that? I thought gravity pulls the gas in - to the center. Also they should make up their mind - do stars emit jets or do black holes emit jets? Or maybe it's the quasars:
https://phys.org/news/2014-11-spooky-al ... years.html
Besides that, my question is: how do they model gravity for a gas cloud? Each atom is pulled towards the center of mass? With a force equal to the total gravity the entire gas cloud mass can create? There is something wrong here. An atom in a sphere, halfway between the surface and the center, would be pulled towards the center with less force than an atom on the surface, because that atom on the surface has all the mass on one side. The atom at half the radius has some mass on one side, and some mass on the other.
Is this reasoning correct?
If it is, then it's another problem for those that want to have gas clouds collapse on themselves just because of gravity, then explode into stars, then keep a spherical form quite constant for billions of years of explosion...
(replaced "molecule" with "atom" because this is about hydrogen clouds)
And another question: Why is there magma inside the Earth?
Is it because of the meteorites that formed the Earth just smashed into each other at high speed? Even if they can't replicate the formation of a planet with a computer model now.
Fo a sphere with uniform density, its g field outside the sphere is modeled as a point mass M at the sphere center, but not true for other density distributions and object shape. To find g within the sphere, we have to use calculus from first principle. I think g is maximum at surface and drops to zero at center. If the sun's surface is gaseous, the gas cannot escape unless with escape velocity. g is zero at the center of the sun, but its pressure is maximum. Fo this reason, it is believed the core of the sun is hot, maybe another form of dense solid state matter.
The core of the earth is likely molten iron as the density of the earth is about slightly less than that of liquid iron; being at high pressure, may be hot as well.
Chan Rasjid.
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Re: Point sources of gravity
Yes, g drops while inside the celestial body. Meaning gravity would have a harder time to defeat pressure, compared to the situation where we consider just a point in the middle of the star as the source of gravity. Meaning - it would be even harder for stars to form from hydrogen that just clumps together because of gravity.Chan Rasjid wrote: If the sun's surface is gaseous, the gas cannot escape unless with escape velocity. g is zero at the center of the sun, but its pressure is maximum. Fo this reason, it is believed the core of the sun is hot, maybe another form of dense solid state matter.
The core of the earth is likely molten iron as the density of the earth is about slightly less than that of liquid iron; being at high pressure, may be hot as well.
Chan Rasjid.
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Re: Point sources of gravity
The centroid of any system, subatomic to astronomic, is the focus, rather than the source, of the pressure field that manifests gravitation, as well as EM pressure, nuclear force, etc... and light. Therefore it is unnecessary that any object be at the center of gravity [aka center of mass], yet [measurements of] the field momentum will appear to be "virtually" phenomenal at that locus, ie. the object behaves as though all its mass were located there, as in the mundane example of a basketball. It is possible for a star or planet to be a hollow object and still behave as a gravitational sink, however the observed momentum of large objects in space infers the much larger mass we attribute to these objects, eg. 5.97 x 10^24 kg for the earth. The lower density of materials near the surface do not allow for a hollow earth. That accepted, the core of a galaxy also manifests as the galactic system centroid, in that virtually all the mass appears to be centered there, resulting perhaps in the illusion of a super-dense BH, yet just as possibly indicating an empty hole, which is what we "see" when we look there!
Truth extends beyond the border of self-limiting science. Free discourse among opposing viewpoints draws the open-minded away from the darkness of inevitable bias and nearer to the light of universal reality.
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