# C-ship

```Hi Steve,

About your relativistic flight simulator. Did you have the same thing in
mind as John Walker, ie. making still raytraced images? Or did you want to
make a more simple "lines-only" version that could show "real-time" images?

The problem with John's simulator is that he almost certainly cannot
simulate moving objects in the field of sight. For example a rotating disc
with radial lines would not show as disc with spiral lines for an observer
at rest.

How far is your embryonic simulator? Have you already done some programming
or are you still thinking how to program it?

Since some years I had in mind to make some simulator too, but haven't risen
above the the paperwork yet. Even if you know what the several relativistic
effects look like, it stays very hard too imagine them all together. And as
far as I can see it one can't just overlay all effects without having them
in the right order.
to use 3D red/blue glasses. My guess is that this may be usefull for a
relativistic version.

What I asked John Walker was that I would expect curved lines in the SHUTTLE
and FLYTHRU movies. I think this curvature would be result of the finite
travel speed of light, ie. light from further objects reach the observer
later than the light from nearer object. Take for example a straight line
moving towards you:

----------------
||
\/                (seen from above)

<You>

The light from the edges of the line take longer to reach your eyes than the
middle of the line. This means that you always see the edges at an older
time than the middle. When the line is not moving that does not make much
difference because at that older time they were at the same place. But as
the line start moving it will look as if it is bend, with the middle most
forward.
You will see the line as follows:

---===****===---

Where * looks near, = a bit further away and - furthest away.

What would you expect?

Timothy

```