On Fri, Jun 26, 2015 at 11:43 AM, Tim <tim@little-possums.net> wrote:

On Fri, Jun 26, 2015 at 11:15:33AM +0200, Knapp wrote:
> I would think predicted position would be a cone for a ship with a
> fast vector and a sphere for one sitting, "still".

No -- as it happens, they're the same shape. The relative motions
available to a moving body in vacuum are identical to those of a
stationary one.

> The cone might bend or even split (more like a hole in the cone), if
> it is interacting with a gravity well.

Gravity wells have predictable effect, so over reasonably short
timescales have negligible effect on uncertainty in position.

- Tim

Give point A still.

Ship B, 1g drive.

I: If B has a vector 10 units long in a direction over 1 second and no thrust then the next point is point.

II: If B starts still and gives 1g for one second then the possible location points will be sphere.

If you add I + II you get a sphere that is 10 units away.

So, OK.

Douglas E Knapp

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