[LeGrande]

I just thought of a simpler example, duck hunting. If you are in the back of a pickup and a duck comes flying by at 60 mph you have to lead it by a few degrees to hit it. Now lets say you are in the pickup driving 60 miles an hour by a pond with a duck sitting in it. Well if you want to hit the duck you are going to have to lead it by a few degrees.

The angle of lead will be precisely the same in both circumstances, it doesn’t matter whether the bird is flying 60 mph and the truck is stopped or the Truck is moving 60 mph and the bird is stopped, the lead angle will be the same. It is the exact same analogy with Pluto orbiting a stopped Earth or a spinning Earth and a stopped Pluto.

[mrjesse]

Said LeGrande:I just thought of a simpler example, duck hunting. If you are in the back of a pickup and a duck comes flying by at 60 mph you have to lead it by a few degrees to hit it. Now lets say you are in the pickup driving 60 miles an hour by a pond with a duck sitting in it. Well if you want to hit the duck you are going to have to lead it by a few degrees.

The angle of lead will be precisely the same in both circumstances, it doesn’t matter whether the bird is flying 60 mph and the truck is stopped or the Truck is moving 60 mph and the bird is stopped, the lead angle will be the same. It is the exact same analogy with Pluto orbiting a stopped Earth or a spinning Earth and a stopped Pluto.

That's the wrong analogy. You're talking above about the transverse velocity of the observer. (Transverse means sideways.) The question of Pluto is a angular velocity issue!

So the real question is "If you were on a merry go around, rotating 10 degrees in the time it would take your bullet to reach the stationary duck, how far would you have to lead?"

And the answer is: If the duck is moving, then yes, you have to lead. But if both you and the duck are in place and not moving, except the platform you are standing on is rotating, then you do not need to lead because the instant the bullet leaves your barrel, it'll travel in a straight line to the duck. (Assuming, of course, that the tip of your barrel is over the center of the merry go around.)

-Jesse