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Post by echnaton on Nov 3, 2010 13:05:50 GMT -4
I think it is pertinent to point out that your analogy of the projectile would fail to make you point even if true. The projectile attitude in your example does not follow a path that is results from a string at the center of the earth attached to the center of gravity of the projectile. Your Apollo diagram indicates the CSM would make one rotation during one orbit. It this were to be applied to a projectile relative to the center of the earth the attitude would be almost unchanged. A projectile flight of 8 miles would cover only about 1/1000th of the circumference of the earth resulting in correspondingly less change in attitude. Care to clarify this apparent discrepancy?
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Post by echnaton on Nov 3, 2010 13:07:46 GMT -4
The LCM is not a broomstick, it has a regular shape. Care to define what a regular share is in terms of gravitational pull and how this applies differently to the CSM and a broomstick? |
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Jason
Pluto
May all your hits be crits
Posts: 5,579
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Post by Jason on Nov 3, 2010 13:13:10 GMT -4
Interactions with the air? So you think that it's air which makes the projectile turn? And why wouldn't also ait exert the same force on all the points of the projectile like gravity does? That one's easy - the projectile is traveling in one direction, so the force of air resistence is from one direction. Since it's coming from one direction it can't affect all points of the projectile equally - it can't reach all points of the projectile equally. |
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Post by echnaton on Nov 3, 2010 13:13:26 GMT -4
You are the one member of the forum that has a misconception. The rest of us do understand how this works. Gravity does not act as a string attached to the center of gravity, center of mass or center of anything. It accelerates all points of the CSM equally. As long as you persist in this folly and focus on one member, all you examinations of Apollo will fail to convince anyone who knows even the rudiments of physics. And I repeat again: If you are really right, then show me a serious scientific article which backs you up! Any of you guys or gals who are familiar with literature of orbital mechanics willing to help out in providing some references. Not that citations will be headed by inquisitivemind, but they will provide completeness for other readers. Or if my conception is wrong, please correct me. |
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Post by echnaton on Nov 3, 2010 13:17:12 GMT -4
[The green line means that the corresponding trajectory burns less fuel that the trajectory along the red line. The two trajectories are possible, but the trajectory along the green line is optimal in fuel concumption. Although the diagram may not be a accurate description of the flight path, I don' think that the general idea is an issue of contention here. |
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Post by theteacher on Nov 3, 2010 13:18:50 GMT -4
Two questions just to clarify my understanding of your stance: 1. Do you know what "tidal lock" is? 2. What will be the "natural" attitude of a broomstick left for a while orbiting the moon? The LCM is not a broomstick, it has a regular shape. Well I chose the broomstick because of its supposed regularity :-) What do you exactly mean by "balanced"? I mean what do you think the engineers have done specifically to reach the "balance"? Forget the broomstick. Take a perfectly "balanced" bar or rod of any material in the shape of a broomstick - a couple of meters long or longer, a couple of centimeters thick with the "center of gravity" right "in the middle" of it. How will the attitude of that object be in orbit around the Moon (or the Earth for that matter) after having been left there for a longer while (weeks or more)? Can you be more specific? By the way: You forgot to tell me, if you know what "tidal lock" is? |
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Post by chew on Nov 3, 2010 13:25:08 GMT -4
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Post by echnaton on Nov 3, 2010 13:25:34 GMT -4
Interactions with the air? Not sure what you mean by "turn." I said it would make a projectile tumble. And why wouldn't also ait exert the same force on all the points of the projectile like gravity does?If the air exerted the same force (that is pressure) on all point of an airplane at the same time it could not fly. |
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Post by echnaton on Nov 3, 2010 13:32:34 GMT -4
Concerning a broomstick, the way it is made it is unbalanced and it will not be horizontal; it's center of gravity is not at the middle of it; Define "middle?" How have you determined the center of mass of the CSM and how that changes over the flight? How have you determined the "middle" of an irregular object like the CSM as different from the center of mass? |
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Post by inquisitivemind on Nov 3, 2010 13:33:58 GMT -4
If you really belive what you say, then I have nothing more to add.
You should go see real scientists so they could explain you real physics.
Anyway, it's useless that I discuss you because you have the whole knowledge and I'm just an idiot who has to bow before you.
However, I dare you to provide me with a serious scientifc article which backs up your claims.
All you do is to stack free assertions you never care to prove.
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Post by inquisitivemind on Nov 3, 2010 13:37:55 GMT -4
Concerning a broomstick, the way it is made it is unbalanced and it will not be horizontal; it's center of gravity is not at the middle of it; Define "middle?" How have you determined the center of mass of the CSM and how that changes over the flight? How have you determined the "middle" of an irregular object like the CSM as different from the center of mass? I say that the natural orientation of the CSM is not far from horizontal. I don't know exactly where the center of gravidy is, but it must not be very far from its center. The CSM may not be perfectly horizontal, but it's closer to horizontal than vertical. And the natural orientation it has, it naturally constantly keeps it relatively to the moon as it orbits, and it can only be contradicted by a push on the lateral reactors. |
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Post by echnaton on Nov 3, 2010 13:42:15 GMT -4
f you really belive what you say, then I have nothing more to add. You should go see real scientists so they could explain you real physics. Anyway, it's useless that I discuss you because you have the whole knowledge and I'm just an idiot who has to bow before you. However, I dare you to provide me with a serious scientifc article which backs up your claims. All you do is to stack free assertions you never care to prove. Sorry for not being able to quote orbital mechanics references off the top of my head. My training is actually in quite a different field. I am primarily "stacking" questions to ask you to clarify the differences between your assertions and what I have read elsewhere from various sources that, to the best of my knowledge, are accepted as correct. If you want to take you ball and go home rather than answer a few questions, you are welcome to do so. Your claim. your proof! |
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Post by echnaton on Nov 3, 2010 13:45:59 GMT -4
I say that the natural orientation of the CSM is not far from horizontal. I don't know exactly where the center of gravidy is, but it must not be very far from its center. The CSM may not be perfectly horizontal, but it's closer to horizontal than vertical. That is pretty vague. How have you determined "closer to horizontal than vertical" to be correct. |
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Post by Daggerstab on Nov 3, 2010 13:48:17 GMT -4
I say that the natural orientation of the CSM is not far from horizontal. (...) The CSM may not be perfectly horizontal, but it's closer to horizontal than vertical. No. Look up "gravity gradient stabilization". Even if gravity's influence was strong enough on Apollo's time frame, the gravity gradient would orient the CSM vertically, with its long axis pointing towards the Moon - nose down or engine nozzle down. Speaking of satellite stabilization, please look up the number of methods used in it and think hard why they are needed... |
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Post by chew on Nov 3, 2010 13:51:24 GMT -4
You claim a constant horizontal path around the Moon. Show us your math. You just admitted you don't know where the center of mass is, so your entire theory about centrifugal forces causing the CSM to rotate to a horizontal position is ludicrous.
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