Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Petrochemicals on 27/05/2021 20:35:43
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Given that the sun is a big ball of plasma gas that was created through gravitational collapse but has since expanded due to its heat, could the core of the sun be in negative gravity territory? I understand that the gravity of earth decreases toward the inner core, could the sun's core actually repel matter?
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I see no reason to assume so. If it was a perfect sphere, the net gravitational force at the exact center would be zero. The kinetic energy of the particles it is composed of bouncing off of each other is what keeps it from collapsing due to gravity.
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Any 'body' has mass, and mass is correlated with positive gravity, meaning that if you took the core of the body away and replaced it with a hollow ball of much less mass that is strong enough to take the pressure, the body in question (sun say) would have less gravity. Hence the core adds to the gravity, and contributes positively.
There is such a thing as negative mass density, and it very much does repel.
Imagine an infinite grid of objects of equal mass at regular distribution. Each will just sit there, being balanced in all directions by gravity from all the objects distributed evenly around it. Now consider the same arrangement but with one of the objects missing. This creates said negative mass, resulting in a chain reaction starting with the immediate neighbors of this 'hole'. All the objects will, by negative gravity, be repelled by this low density region, making the region bigger and accelerating the effect.
Look up the dipole repeller for an example of exactly this, a region of negative gravity expelling all nearby galaxies in all directions. This was apparently only discovered 4 years ago. There's also the cold spot repeller, even larger and further away.
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could the core of the sun be in negative gravity territory?
No
If there was some "magic stuff" which repelled mass then the place you could not find it is in the middle of a big sphere of mass.
It would have been repelled out.
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An arch is only stable because of the mass above the arch impresses on the arch. The more weight in the whole the more stable the arch. If a star collapses gravity at the creation of fusion and is only expansive due to fusion, the collapse of gravity seems only logically perpetuated and extended by the fusion, that is to say that the fusion creates further and increaced collapse. I suppose a better way of summarising it would be if the collapse has ceaced so would fusion?
At the peril of being put ino new theories, it would some how lead to the fusion leading the acceleration of gravity away from the centre toward the fusion areas. Would the gravitational collapse lead to strange characteristics?
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If a star collapses gravity at the creation of fusion and is only expansive due to fusion, the collapse of gravity seems only logically perpetuated and extended by the fusion, that is to say that the fusion creates further and increaced collapse
Perhaps you could rephrase this? I don't understand what you are trying to say.
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If a star collapses gravity at the creation of fusion and is only expansive due to fusion, the collapse of gravity seems only logically perpetuated and extended by the fusion, that is to say that the fusion creates further and increaced collapse
Perhaps you could rephrase this? I don't understand what you are trying to say.
Could there be a big void of space time at the heart of every star held by fusion due to the collapse of gravity?
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These speculations are very. interesting, But as yet they can't be backed up by experimental evidence.
The necessary evidence will not become available until we closely examine a star. When will we be able to do this?
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Could there be a big void of space time at the heart of every star held by fusion due to the collapse of gravity?
If the center of a star was empty, the surrounding plasma would quickly rush in to fill it.
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Could there be a big void of space time at the heart of every star held by fusion due to the collapse of gravity?
If the center of a star was empty, the surrounding plasma would quickly rush in to fill it.
Would the plasma be able to fill it. The centre of the star would be a region where time stood still.
Like the "event horizon" surrounding a Black Hole, where something falling into it, is seen as forever frozen in time?
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Would the plasma be able to fill it.
Yes.
The centre of the star would be a region where time stood still.
No, it wouldn't.
Like the "event horizon" surrounding a Black Hole, where something falling into it, is seen as forever frozen in time?
The core of a star isn't at all like a black hole's event horizon.
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Obviously, to settle this matter, we need to get some actual evidence of what's at the core of a star.
We have a star close at hand, in the form of our Sol. Would it possible to design a probe that could penetrate deep into Sol, and get some instrumental readings, and possibly photographs of the core?
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Obviously, to settle this matter, we need to get some actual evidence of what's at the core of a star.
Not really. We know enough about physics to know that the center of a star isn't empty.
Would it possible to design a probe that could penetrate deep into Sol, and get some instrumental readings, and possibly photographs of the core?
That would take some extreme super-tech. The Sun's surface alone is hot enough to melt any known material, much less the deeper layers of the Sun.
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Obviously, to settle this matter, we need to get some actual evidence of what's at the core of a star.
We have a star close at hand, in the form of our Sol. Would it possible to design a probe that could penetrate deep into Sol, and get some instrumental readings, and possibly photographs of the core?
No.
Not even if we went at night.
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An arch is only stable because of the mass above the arch impresses on the arch. The more weight in the whole the more stable the arch. If a star collapses gravity at the creation of fusion and is only expansive due to fusion, the collapse of gravity seems only logically perpetuated and extended by the fusion, that is to say that the fusion creates further and increaced collapse. I suppose a better way of summarising it would be if the collapse has ceaced so would fusion?
At the peril of being put ino new theories, it would some how lead to the fusion leading the acceleration of gravity away from the centre toward the fusion areas. Would the gravitational collapse lead to strange characteristics?
Gravity does not collapse; ever (as far as we know).
The star collapses because of gravity.
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Given that the sun is a big ball of plasma gas that was created through gravitational collapse but has since expanded due to its heat, could the core of the sun be in negative gravity territory? I understand that the gravity of earth decreases toward the inner core, could the sun's core actually repel matter?
Newton's shell theorem puts paid to your idea. A hollow sphere exerts no gravitational effects on any object inside the shell. No matter what its position is inside. Therefore we can make this cavity progressively smaller and smaller and at no time will there be any repulsive effects.
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Why appeal to Newton's "shell theory"? Newton was a 17th century scientist.
Because shell theorem is still correct. The passage of time doesn't change that.
Isn't this "Strong Force" a "repulsive" one
Only at very close range. Beyond that, it is strongly attractive until you get a little ways out of the nucleus. Then it becomes so weak as to be practically non-existent.
which lets protons overcome the inner force of Gravity.
Protons don't have to overcome gravity, as their electrostatic repulsion already massively overwhelms any gravitational attraction they have between each other.
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Ah, all right. Sorry if that sounded snappy. I thought you may have been trying to imply that we couldn't trust Newton's physics.
Thanks Kryptid, I don't blame you for sounding snappy. It's the same feeling I get, when no-one seems to understand.
As regards Newton, I'm not sure. His ideas work in the Solar System. Planetary movements, and all that.
It would be nice if his ideas extended to the Universe as a whole. That would make sense.
Perhaps they do, and we are being misled by attaching an undue significance to the "speed of light".