I do "physics and stuff" for a living
, and I am withholding comment, as I've come to be of the opinion that people are far more inclined to believe what they want, than to learn what is so.
Even so ... simple experiment for the uninitiated:
- Buy an icepick.
- Buy any good-sized roast.,
- Place the pointy end of the ice pick on the thickest part of the roast.
- Slam the palm of your hand on the back of the ice pick's handle.
- Note that equal force is being applied at both ends of the ice pick ... you know, all that stuff about equal and opposite reaction.
- Note that the pointy end of the ice pick penetrates the roast, and the handle does not penetrate your hand.
- Figure out why, and you'll know why a rifle can knock the shooter on his butt, but the fired projectile can't.