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.
Viviane
JoinedPosts by Viviane
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280
the flood, mammoths, elphants, and food.
by Crazyguy inmy question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.
also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .
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Viviane
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280
the flood, mammoths, elphants, and food.
by Crazyguy inmy question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.
also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .
.
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Viviane
Meanwhile, in the real world:
2) If the body is a spherically symmetric shell (i.e., a hollow ball), no net gravitational force is exerted by the shell on any object inside, regardless of the object's location within the shell.
Yeah, exactly, no NET force. If you can't grasp the idea of "not force" and compare that to "no NET force", I really can't help you. That's EXACTLY what I have been saying. Thanks for practically quoting me.
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280
the flood, mammoths, elphants, and food.
by Crazyguy inmy question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.
also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .
.
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Viviane
Viv: As I have now used math i assume it will be fair if I ask you to clarify a few of your more puzzling remarks "with math"? You know, if you insist it of others, i suppose that would only be fair?
You can assume anything you like. As I said, I've already done the math I argued about in the thread. It's not my issue if you are puzzled.
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280
the flood, mammoths, elphants, and food.
by Crazyguy inmy question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.
also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .
.
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Viviane
I did not claim this. I claimed the gravitational field exerted by a hollow sphere at an interior point was zero. Since you are so crazy that people ust show you math here is my derivation, properly there are a few constants wrong here or there:
Let's see. You wrote:
I will be happy to help you with the required integration if neccesary:
That's offering to do math. Not only have you not done it, you are denying that you ever offered. People do remember what you wrote, you know.
Now, could you be so kind as to explain what is wrong in this derivation and could you kindly (if you prefer, WITH MATH!!!111 and without the arrogance and name-calling) explain the meaning of:
There has been no arrogance or name calling. Stop with the butthurt and discuss like a grownup.
So, to answer, what is wrong with it? The opening statement. The whole point of shell theorem is to be able to calculate gravitational effects between two bodies. You ignore that and the entire point of it out of the gate. Anyway...
Your equations appear to be correct from a quick glance and show exactly what I said, net gravitaional effect is zero. It doesn't mean "no gravity exists". Explain how mass can fail to produce a gravity field. So far you're doing an excellent job of supporting me. I appreciate that, sincerely.
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109
Topics Ive Been Pondering On
by JWINQUESTION inthis is my first post on here so bear with me.
currently i am still an active jw with serious questions about the jw org.
i was hesitant signing up but really need as much input from the people on this forum to get a clear understanding on things.
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Viviane
You won't hear any five-syllable swears
You're not doing it right, then.
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280
the flood, mammoths, elphants, and food.
by Crazyguy inmy question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.
also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .
.
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Viviane
Caedes: The intuition behind your argument is correct, however (by definition) the gravitational field on the inside of the hollow sphere due to the sphere is zero. The question is if a gravitational field of zero mean there is no gravity; I would tend to say yes because otherwise I would not know what no gravity means. Viv seem to distinguish between no acceleration and no total acceleration which is so silly I think it is beyond me to correct that misunderstanding.
Show me, mathematically, how mass produces zero gravity and I'll agree. You promised math. We're waiting.
Also, BTW, nothing here is "by definition". It's something that has been proven, it was not by fiat. Your statement shows you STILL are not grasping shell theorem. The entire point, again, is that the entirely of the mass of a sphere has a net gravitational effect internall of zero such that any calculations between two bodies can be done using center mass. It, in no way, doesn't, hasn't nor ever will say there is no gravitational field inside of a hollow sphere.
Mass warps space. If you disagree, please, for the love of science, show us all how. I'm just guessing, but I will bet you will never ever do that and will continue to make smaller and smaller arguments until you eventually say the exact same thing I have been saying all along and simply claim I misunderstood and you were right the entire time.
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280
the flood, mammoths, elphants, and food.
by Crazyguy inmy question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.
also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .
.
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Viviane
You quite plainly did not. That you insist you did, and are unable to substantiate your claims except insisting it is so is quite revealing.
It reveals that you are out of your depth. However, since I'm such a giving person, I quote myself again for you. Seriously, try reading next time. You'll look less foolish. This is the second time you've claimed I didn't write something I did and you've been proven wrong.
The shell theorem shows that gravitational acceleration between two bodies can be calculated using the center of those bodies because, effectively, the TOTAL gravitational acceleration inside nets out to zero as can be shown using two perfectly spherical but hollow bodies and how, relative to the internal coordinates, gravitational acceleration is calculated relative to ANOTHER body either inside or external to the spherical hollow mass (that's the radius you were missing, the second body). That doesn't mean there IS NO GRAVITY or that it is not stronger inside the body in one corrdinate than in another place. It just means that it NETS to zero.
There is also a shell theorem application for electrostatic systems. A rough analogy would be that, inside the bubble of the universe, the total amount of energy = zero yet we can still utilize energy to get work done.
Also, you insinutated you could do all the math on this and that I couldn't. Please show your math.
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280
the flood, mammoths, elphants, and food.
by Crazyguy inmy question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.
also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .
.
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Viviane
I notice you re-phrased what I wrote so as to create a strawman. Firstly, as is apparent in the context, I was treating the newtonian/relativistic example seperately. Secondly, you are talking about the effect of the mass *of an object inside the shell* whereas my statement was (and this is apparent if you read it) about the gravitational field *inside a hollow shell*. That you insert an object inside the hollow shell and discuss the gravitational effect *of that object* is the strawman
Please show my strawman and the math you promised to help with. The shell theorem deals with BOTH mass internal and external mass. You specifically earlier claimed I was moving the goalposts by even mentioning GR, now I'm creating a strawman by literally quoting you and pointing out your error?
Please, please, please show me where I, in any way, changed your words to create a strawman. The ENTIRE conversation has been about people saying "there is no gravity inside a hollow shell". The FIRST person to even mention that the whole point of the shell theorem is to be able to do grvitational computations between external bodies was me.
So, your claim is that now, somehow, me talking about the point I brought up to explain shell theorem to you is somehow me creating a strawman?
I would love to see the chain of logic that allows you to think that me bringing up my own point is turning your argument into a strawman.
And you promised math and haven't delivered.
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280
the flood, mammoths, elphants, and food.
by Crazyguy inmy question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.
also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .
.
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Viviane
So you disagree with this point? Can you eleborate then in what sense the radius of the second body enters into the derivation not covered by my description? Specifically, does the shell theorem in your oppinion not cover the case where a non-spherical body is inside a spherical shell?
I already did. I'm not re-typing it because you didn't grasp, read my post it or read a paper on it.
Interesting. There is some basic confusion here on the meaning of acceleration. Try to give a counter example. How does the "total" acceleration of a body differ from it's acceleration?
I already gave an example in the form of an alalogy using the elctrostatic version of the shell theorem. I'm not re-typing it because you didn't read or get it, whichever it is.
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280
the flood, mammoths, elphants, and food.
by Crazyguy inmy question is since it looks as though mammoths were alive after the flood and we know elephants are then how much food was needed to feed just these four animals for the time they were on the ark.
also was the ark, 500 feet long, big enough to hold the amount of food needed for just these 4 animals.. .
.
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Viviane
Because of any friction, the almost weightless floater would start falling from lower and lower heights from the center, would be moving slower and slower, come to a standstill or hangstill at the center, ceased to be accelerated, for there is no gravitational pull in either direction at the center of such an ideal sphere.
Friction? Show me, mathematically, what that has to do with it? Friction from what? Air? Now the shell isn't hollow, there is mass inside and you're talking about a completely different thing that you were before. And, gravitational acceleration doesn't cease to exist, it's simply perfectly balanced in all directions.
If you disagree, please show me how 1)air is not mass and 2) how mass can avoid warping space because it's inside of a shell.