|
Post by lsvalgaard on Nov 9, 2011 7:08:56 GMT
Dr Svalgaard have you yet done a prediction for SC25 ? Thanks for your answers. I prefer read your graphs than those of vukcevick, they are more finished and careful A prediction of SC25 is not possible at this point. A guess would be that SC25 would be smaller than SC24.
|
|
|
Post by hairball on Nov 11, 2011 19:17:13 GMT
Dr. Svalgaard,
I've believed that stars are formed when gravity squeezes atoms together, electrostatics push them apart, thus warming them, then gravity squeezed them back together again and so on . . . until the kinetic energy of the atoms in the resulting plasma overcame electromagnetism and allowed fusion.
I'd believed that gravity was the source of this energy.
Learned people have recently told me that this is creating energy out of nothing - that gravity cannot warm things.
Am I completely wrong to think that the force of gravity is an actual Force that can do work and heat things up?
|
|
|
Post by lsvalgaard on Nov 11, 2011 21:09:15 GMT
Dr. Svalgaard, I've believed that stars are formed when gravity squeezes atoms together, electrostatics push them apart, thus warming them, then gravity squeezed them back together again and so on . . . until the kinetic energy of the atoms in the resulting plasma overcame electromagnetism and allowed fusion. I'd believed that gravity was the source of this energy. Learned people have recently told me that this is creating energy out of nothing - that gravity cannot warm things. Am I completely wrong to think that the force of gravity is an actual Force that can do work and heat things up? If you compress a gas it heats up. If you have ever used a hand-operated pump to inflate a bicycle tire you would know [the pump gets hot]. Gravity when the star is forming compresses the interstellar gas and the forming, new-born star thus gets hot inside. This continues until the center gets so hot that the atoms are moving so fast that they can overcome their mutual electrostatic repulsion and fuse. The fusion [of four hydrogen atoms to one helium atom] releases energy [because the helium has less mass than the hydrogen it is made from and Einstein's E=mc^2 comes into play]. The energy released keep the star hot so halts the contraction due to gravity. So the star just sits there and 'burns' away. When the hydrogen is used up, the star begins to contract again [gravity doing its thing], this heats up the star some more and now the helium can begin to fuse creating e.g. oxygen and carbon. The further development depends on the mass of the star, some will eventually explode, while others [like the Sun] will just slowly fade away.
|
|
|
Post by hairball on Nov 11, 2011 21:38:41 GMT
Thank you. It's beautiful.
But, please, gravity is a source of energy?
EDIT: Erm, it's been suggested to me that once compression has taken place that gravity has no further effect - surely this is wrong? In your example of the bicycle pump - the gas can only be warmed by gravity compression once - so I've been told.
|
|
|
Post by france on Nov 12, 2011 21:59:36 GMT
Dr Svalgaard have you yet done a prediction for SC25 ? Thanks for your answers. I prefer read your graphs than those of vukcevick, they are more finished and careful A prediction of SC25 is not possible at this point. A guess would be that SC25 would be smaller than SC24. thanks Dr Svalgaar. I thought it was possible with what happened with the coronal hole at the North hemispher few months ago About the gravity : I read planets gravity and sun gravity are indissociables ? Is it right ? sun flow and planets motions are linked because of the distance that parts them (see Newton Equation of universal attraction F=GMm/d2) It seems evident to me that when distance changes, F changes consequently. Is it right ?
|
|
|
Post by lsvalgaard on Nov 12, 2011 22:05:42 GMT
A prediction of SC25 is not possible at this point. A guess would be that SC25 would be smaller than SC24. thanks Dr Svalgaar. I thought it was possible with what happened with the coronal hole at the North hemispher few months ago Only when the new polar fields has built up and has become stable can we use it for prediction, and that I don't expect for several years.
|
|
|
Post by france on Nov 12, 2011 22:25:32 GMT
Dr Svalgaard I was modifing my post when you answered it. Thanks !
About the gravity : I learnt planets gravity and sun gravity are indissociables ? Is it right ? sun flow and planets motions are linked because of the distance that parts them (see Newton Equation of universal attraction F=GMm/d2)
It seems evident to me that when "d" changes, "F" changes consequently. Is it right ?
But if F is modified it could contribute to affect the gravity and the equilibrium beetween the two forces that make the sun in place (gravity and pressure called hydrostatic equilibrium).
If I'm wrong, how this modification occurs between gravity and pressure force inside the sun ? Because it occurs isnt'it ?
|
|
|
Post by france on Nov 17, 2011 1:11:09 GMT
Dr Svalgaard my question is it so stupid ? May be my english is bad ;( I find some graphics here, what do you think about ? www.astronomynotes.com/starsun/s7.htmTo resume my question is ! As you explain with the pump and gas to compare what happens in the sun. What substitute the hand in your comparison ? Because without a hand gaz will not shake ! what is the hand in the sun activity ? I understand like that : gravity is the pump gas is the gas but I don't understand what is the hand that speeds up the pump ?
|
|
|
Post by lsvalgaard on Nov 17, 2011 5:59:05 GMT
Is good. gravity is the hand the sun's volume is the pump the gas is the air Now, you might ask: "but the hand moves and gravity is constant [at a given place] so no movement". But imagine the pump is an infinitely long thin cylinder and your hand push all the time. Same with gravity, it pushes all the time and if there was nothing to push back, the material would be pushed infinitely far into a black hole. What stops that is the heating of the gas that exerts a pressure against gravity and prevents the infinite collapse.
|
|
|
Post by justsomeguy on Nov 17, 2011 12:21:48 GMT
Which is proven, as when the heat stops and the gravity causes the stars collapse you can get a black hole, just gravity ...
|
|
|
Post by lsvalgaard on Nov 17, 2011 14:45:49 GMT
Which is proven, as when the heat stops and the gravity causes the stars collapse you can get a black hole, just gravity ... If the star is massive enough, yes. Smaller stars end up as white dwarfs or neutron stars where the stiffness of the material prevents further collapse.
|
|
|
Post by france on Nov 17, 2011 16:14:04 GMT
gravity is the hand the sun's volume is the pump the gas is the air Now, you might ask: "but the hand moves and gravity is constant [at a given place] so no movement". But imagine the pump is an infinitely long thin cylinder and your hand push all the time. Same with gravity, it pushes all the time and if there was nothing to push back, the material would be pushed infinitely far into a black hole. What stops that is the heating of the gas that exerts a pressure against gravity and prevents the infinite collapse. ok thanks dr I understand but my question is : why the hand moves ? Because of the gas is the answer probably. So is not what you explain it's the opposite. The gravity (hand) pushes the gas. And in the equation F=G M1M2/d2 gas formulae does not appear though in explanations it's gas that exerts a pressure. I suppose this pressure is not always the same as in our atmosphere and all planets too ! even the sun ! So it seems evident to me that F must be different occording the distance and according pressure too ! is it right ?
|
|
|
Post by lsvalgaard on Nov 17, 2011 17:39:42 GMT
gravity is the hand the sun's volume is the pump the gas is the air Now, you might ask: "but the hand moves and gravity is constant [at a given place] so no movement". But imagine the pump is an infinitely long thin cylinder and your hand push all the time. Same with gravity, it pushes all the time and if there was nothing to push back, the material would be pushed infinitely far into a black hole. What stops that is the heating of the gas that exerts a pressure against gravity and prevents the infinite collapse. ok thanks dr I understand but my question is : why the hand moves ? Because of the gas is the answer probably. So is not what you explain it's the opposite. The gravity (hand) pushes the gas. And in the equation F=G M1M2/d2 gas formulae does not appear though in explanations it's gas that exerts a pressure. I suppose this pressure is not always the same as in our atmosphere and all planets too ! even the sun ! So it seems evident to me that F must be different occording the distance and according pressure too ! is it right ? The hand [gravity] moves because mass curves space around it and matter slides down the curve. The gas has pressure because it gets hot and the atoms move faster and therefore push harder.
|
|
|
Post by france on Nov 18, 2011 18:17:41 GMT
The hand [gravity] moves because mass curves space around it and matter slides down the curve. The gas has pressure because it gets hot and the atoms move faster and therefore push harder. fine dr Svalgaard, why do you think the attractive force can't have any kind of matter in the solar activity ?
|
|
|
Post by lsvalgaard on Nov 18, 2011 18:26:42 GMT
The hand [gravity] moves because mass curves space around it and matter slides down the curve. The gas has pressure because it gets hot and the atoms move faster and therefore push harder. fine dr Svalgaard, why do you think the attractive force can't have any kind of matter in the solar activity ? Because it is too weak.
|
|