Wow this is a new low!!

It's called conservation of momentum. What's so unbelievable about that?

"The momentum of an isolated system cannot change, ever, for any reason, no matter what happens internally"

If you're sure it's wrong, then, as ImagingGeek suggested, ACTUALLY BUILD IT AND CLAIM YOUR NOBEL PRIZE!!

As with perpetual motion, this will make you richer than God.

But the advantage here is it's much easier and cheaper. Just get an old PVC pipe, put a pressurized coke bottle inside, rig up a trigger to release the bottle's nozzle, cap the ends, pull the trigger, sit back and wait for the endless stream of money to roll in.