> > Thrust can only be created when you are pushing against 
> something else. 

> Not true.  It's an "equal and opposite reaction" thing.
> 
> If you were to throw rocks in free space, you would propel 
> yourself in 
> the opposite direction to your rock shower.  It wouldn't make 
> one bit of 
> difference if the rocks that you threw then hit rocks that you had 
> previously thrown.

So you do agree: it is the first rock you are pushing against.

Wouter van Ooijen

-- -------------------------------------------
Van Ooijen Technische Informatica: www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: www.voti.nl/hvu
 

_______________________________________________
http://www.piclist.com
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist