The maths on that link is fairly straightforward and usefully it diagrammatically shows why your net force is zero. It isn't because there is no gravity it's because the forces are balanced.
Winner winner, chicken dinner.
the flood, mammoths, elphants, and food.
by Crazyguy 280 Replies latest watchtower bible
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Viviane
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Viviane
I have already discussed the diference and similarity with the GR and newtonian situation in my other posts. I do not claim mass do not warp space in general. Please show me where I made that statement as I think it is very dishonest of you.
And this is exactly why you are out of your depth. Saying "there is no gravity" is saying "mass doesn't warp space". It's not at all dishonest, you just don't truly grasp the subject.
I have just proven this wrong by my previous post. please oh pretty please don't move the goalpost.
Quite the contrary, you are now moving ever closer to saying the exact same thing I am. I predict it will take 10 more posts before you are agreeing with me and claiming I was wrong the entire time.
And seriously, please stop pretending all these logical fallacies are happening. You've yet to show where a single one occured.
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bohm
Caedes: As I wrote in my previous posts, it depends on the definition of when there is gravity. In my mind defining no gravity as meaning "the gravitational field is zero" is a reasonable definition, however you are free to disagree and say the phrase "no gravity" by definition refer to one being infinitely far away from any mass.
One thing to ponder is in this case the following question: what is the gravity (exactly) inside the sphere? Notice in this respect that the gravitational field is a single vector-valued function over space. Is "gravity" also such a function? Is it a superposition of such functions? I would normally say "gravity" is either the phenomena, or an informal way to talk about the gravitational field.
Before any of the above is taken out of context i wish to add i am talking in the newtonian case.
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Caedes
Winner winner, chicken dinner.
Excellent, you cooking?!
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Vidiot
Oy vey; this is still going on?
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Viviane
In my mind defining no gravity as meaning "the gravitational field is zero" is a reasonable definition, however you are free to disagree and say the phrase "no gravity" by definition refer to one being infinitely far away from any mass.
Except the NET gravitational effect is zero. That in no way means there is no gravity.
Before any of the above is taken out of context i wish to add i am talking in the newtonian case.
It still applies even in that case. It's simply more accurage in a reltavistic sense.
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bohm
Viv: Saying "there is no gravity" is saying "mass doesn't warp space". It's not at all dishonest, you just don't truly grasp the subject.
As I have made clear many times we should distinguish between the GR treatment of this subject and the newtonian treatment.
Now, to say there is no gravity in some area of space is not to deny that mass warp space in general. This ought be self-evident.
Do we agree I have just demonstrated the gravitational field of a hollow shell vanish at all interior points of the shell? Do we agree this mean the acceleration of an object inside the shell will be zero?
Now moving two pages back you wrote:
It's still not true. Please do show the math. I would suggest you pick the exact center of the sphere and, for a good distribution of test points, five random places inside the hollow sphere and run the math. Oh, and please be sure to use relativity when describing the gravity.
I have now done the math in the newtonian case. The acceleration of five test points inside a hollow sphere due to the hollow sphere will be zero. They wont move. If you assume the points have mass and they are present at the same time they will attract each other. Care to do the math in the relativistic case? (hint, use Birkhoffs theorem I wrote about on the previous page)
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Viviane
Excellent, you cooking?!
I made pan sauteed chicken last night with a lemon,, butter, white wine and caper sauce last night, so... sure.
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bohm
Viv: Except the NET gravitational effect is zero. That in no way means there is no gravity.
..it means the gravitational field is zero. You do not have to insert "net" or "effect". I have already demonstrated this:
You are free to insist there is still "gravity" inside it. I am free to insist there is an invisible dragon. From a newtonian POW both are equally undetectable.
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Caedes
Caedes: As I wrote in my previous posts, it depends on the definition of when there is gravity. In my mind defining no gravity as meaning "the gravitational field is zero" is a reasonable definition, however you are free to disagree and say the phrase "no gravity" by definition refer to one being infinitely far away from any mass.
That isn't what shell theorem states, it is saying the forces on one side of the mass are balanced by the forces on the other. If you look at the equations on the link it shows the gravity force (G as per usual) all the way down the page, the fact that the equations sum to zero doesn't mean there is no gravity. I would agree that it is a small distinction but the equations are only telling you what the net effect of gravity is on a mass. Those equations are not telling you that gravity is zero just that there is no net effect of the gravity on your mass.
You are a clever person Bohm and I normally agree with your posts, I just think you have your definitions on this a little mixed up.
