How to inverse a particle emitter

[Chris Angelico]

On Sat, Jun 6, 2015 at 10:10 AM, Dennis Lee Bieber
<wlfraed at ix.netcom.com> wrote:
>         That is in the same class as the "lunar lander" game on my college
> mainframe...
>
>         It did not do validity checking of inputs, with the result that one
> could do
>
> -10 lbs thrust at 180 degrees
>
> and GAIN fuel while decelerating.

Hah! The version I played didn't allow you to specify 180 degrees,
although it did allow negative burns. So you could tweak your fuel
supply by careful negative burning, but it required some balancing
work to actually come to a safe landing.

Of course, if you wanted to just quit out in a hurry, all you have to
do is a straight-down burn of -9999999, and bam, you're on the ground,
with a Captain Haddock style of "We shall end up by arriving, I
suppose".

ChrisA