Post by krw Post by Penny
scrawled in the dust...
Post by carolet
I find the phrase "three point turn" to be inadequate because there are
never three points. If you imagine the car creating a line on the road
as it goes, that line will always have an even number of points. In the
perfect turn, there will be one point where you go into reverse, and
another when you go forward again.
What about the point at which you stopped before commencing the turn?
You are stopped. The instruction is then given so the points are
counted from restarting. Always odd.
What's a point? It seems that the start and end positions count as one
though they won't coincide unless one starts or ends on the wrong side
of the road. It seems the positions near the kerbs count separately.
So counted thus, it does come to an odd number. But why (he innocently
enquired) do the start and end positions count as one?
If you draw a picture (would that I could do so in ascii!) you will get
a curve that crosses itself. If that crossing point counts as one point
and the cusps each count as one, then I think "three-point turn" is
justified. As well as the tricuspoid part, the curve has two tails -
the coming and going parts of the route - they are to be ignored.
Do, as a concession to my poor wits, Lord Darlington, just explain
to me what you really mean.
I think I had better not, Duchess. Nowadays to be intelligible is
to be found out. -- Oscar Wilde, Lady Windermere's Fan