Is emission-less propulsion possible? I believe it is...

[Salviati]

36. Chat GPT is not a content expert.

Chat GPT is a credulous liar, which will produce answer shaped text based on whatever prompt you give it.

There is a step between 2 and 3 that is being forgotten. Those bullets do not get redirected for free. Accounting for energy loss is not the same thing as accounting for their change in momentum. If the scenario is envisioning the bullets being initially fired to the right, and the ship mechanism initially recoiling to the left, then in order to redirect the bullets we're going to have to impart a large impulse (change in momentum) to the bullets, pointing to the left. This will require, by Newtons 3rd law, an equal an opposite impulse on the ship mechanism, pointing to the right.

By whatever mechanism the bullets are redirected, if it's internal to the ship mechanism, in order to get the bullets to reverse direction, the ship will have to reverse direction as well.

Moreover, if Newton's 3rd Law is obeyed, then if all the interactions are internal, that is to say only between the ship and the bullets, then if we complete one full cycle with the bullets in hand, ready to be fired again, then the final velocity of the ship and bullets will need to be zero. Since the system started with zero momentum before the firing, the total momentum of the system must remain zero, regardless of how many, or what type of internal interactions they have. If the ship and bullets are moving together, then the only way this is possible is if they're moving together with a velocity of zero.