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Rotation of Heavenly Bodies 
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#19
Mar1414, 01:56 PM

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#20
Mar1514, 07:12 AM

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Keep in mind that an axis is an imaginary axle. The ferris wheel cars are mounted on axles (axis) that are physically attached (through bearings) to a central axle (axis). Each car is rotating about its axis once per orbit (thank God). All the cars are rotating about the central axis. Also, a point on each axle is continually facing the same direction; not the direction of motion. Distant observer only sees one side of the cars; the observer at the center all sides once. This scenario is only possible with the cars mounted on real axles. Convention would classify the cars as nonrotating celestial bodies. 


#21
Mar1514, 11:56 AM

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Jtban, have you been listening to anything going on in this thread? Looking at your latest post, it doesn't look like you've learned anything since we started. I don't mind helping you, but I feel like I keep correcting the exact same errors.



#22
Mar1714, 09:48 AM

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An axis can be imaginary or real. A real axis is an axle. A point on an axle continually faces the direction of motion of the object to which it is physically attached, like the axle of a car on a ferris wheel. The axle rotates with the object to which it is physically attached. The car rotates independently on bearings and always faces the same direction.
An object moving in a circle has 2 virtual axes: the stationary center of the circle and the center of the orbiting object. Since an axis is imaginary, a point on the axis can be imagined to: 1) always face the same direction, or, to 2) always face the direction of motion. With the former 1), a nonrotating object orbiting the center of a circle and one rotating twice per orbit are indistinguishable. The center sees all sides of the object once per orbit; distant observer sees all sides twice. The latter 2) view doesn't have this anomaly. It just occurred to me while experimenting that a nonrotating object moving in a circle on an axis always pointing in the same direction is impossible. I couldn't duplicate it. A nonrotating object always looked like one rotating twice per orbit, either prograde or retrograde. When researching the subject I became confused because I ran across a blog stating that a nonrotating object is theoretically possible, but that there were no known celestial occurrences. Now I understand why. Took me a while to get to the obvious. Thanks for putting up with me. 


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