---snip from Ken's Post 94---
A simple demonstration - draw a happy-face on an orange, then go into a darkened room and take the shade off of one table lamp (that will be the sun), then hold the orange on your outstretched palm with the happy-face facing you, then spin 360 around counter-clockwise on your heels.
If you do that, then you'll see all phases of the moon likewise pass across that orange.
The orange will NEVER spin in your hand, yet, its happy-face will always remain pointed towards your spinning body!
You can even see more than 50% of the orange's surface (libration) by raising the orange/moon model above and below your eye level. Viewing the orange/moon first with one eye and then the other eye will also cause some libration (caused by parallax.)
When you show a person that demonstration to prove that the moon doesn't spin on its polar axis (only around your body's axis), they will either grok it, or they'll dig their heels in and claim your arm isn't the same thing as gravity.
Of course an arm isn't gravity, but in an accurate model your arm can serve the same purpose.
---/---
You're wrong, and i've detailed why in my posts (for example, the fact that the orange doesn;t rotate WRT your hand is completely irrelevant - all that means is that it's moving and rotating with your hand).
You say that, "all that means is that {the orange} is moving and rotating with your hand?"
OK, but if your hand and orange were both rotating around the orange's center-axis (instead of ONLY around your body's axis as I claim), then wouldn't that hurt when your hand snapped off at the wrist and started rotating along with the orange around the orange's axis?
OR, are you claiming a different spin axis than the orange's center axis?
Trippy, there are only two possible locations for a spin axis in this demonstration, either the orange spins around its own center-mass, or around your body's mass.
If you want to spin the orange around two axes at the same time, then try it again, but this time use your free hand to keep the orange pointed at the same wall as you spin your body 360˚ counter-clockwise. What happened?
From your center-point perspective, did the orange rotate one time clockwise, even though the orange didn't rotate from the sidereal perspective since it remained facing the wall? That's the 0:1 spin ratio. Spin the orange 1.93 times clockwise as your body rotates counter-clockwise, and that's Venus' spin ratio, a
.93:1.
Spin the orange clockwise a tad faster to rotate it a full two times per each 360˚ counter-clockwise spin of your body, and you'll have another 1:1 spin rate, the same 1:1 rate you'd have if you stopped rotating the orange and just spun your body 360˚ counter-clockwise.
Isn't that interesting, that you can have two 1:1 spin rates on both sides of a 0:1 spin rate when astronomical bodies spin down from the clockwise direction? That's basically what Venus is now doing, so it's more than a hypothetical spin-down!
These demonstrations work better if you're honest about the results, and if you also let the results make you think about these relative motions, which are difficult to fully grok until you actually try doing these simple moon models.
Ken