Re: Clockwise without clocks

On Fri, Apr 01, 2005 at 11:40:56AM +0100, Tim May wrote:
> B. Garcia wrote at 2005-03-31 17:11:40 (-0800)
>  > All of these arguments about if wheels turn left or right or things
>  > roll left Vs. right when you're in a cart or whatever, is why I
>  > suggested "forward rolling" and "backward rolling" - from the point
>  > of view of someone looking at it from the side.  If you take a
>  > round log from a tree, and push it away along the ground it rolls
>  > forward - clockwise to an observer looking at it. If you pull it
>  > back to you the thing rolls backward, counter-clockwise to someone
>  > looking at it.
>
>
> Uh, Barry, unless I'm missing something, that doesn't work.  You're
> defining the motion according in terms of an observer looking at it
> from "the side", but there are two sides, and they'll see different
> things.
>
> If I'm rolling this log eastward, for example, an observer to the
> north will see it turning anticlockwise while an observer to the south
> will see it turning clockwise.
Yes, but the person who sees it rolling anticlockwise will always see
it moving to *his* left, and the person who sees it rolling clockwise
will always see it moving to *his* right. The two of them may not
agree which way the log is rolling, but that's beside the point. The
point is that clockwise is consistently "to the right" of the
observer, and anticlockwise is consistently "to the left" of the
observer.


T

--
Once bitten, twice cry...

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