[extropy-chat] unidirectional thrust

[spike]

> bounces at lists.extropy.org] On Behalf Of Damien Broderick
> 
> Every time metal starts spinning when you switch an electromagnet on and
> off, you are making something move that was stationary. I assume the equal
> and opposite force goes into the magnet which is bolted to the floor and
> hence doesn't move because the entire earth takes up the impact. (I do
> realize this is physics 001 territory.) For the same reason, I assume
> nobody would wish to be cushioning a rail gun against his shoulder when he
> switches it on. Or am I missing something elementary here?
> 
> Damien Broderick [still not a physicist]

The earth moves back the other way.  Not very much of
course, being as it is 6E24 kg, but it reacts the same
way any mass would.  Momentum is conserved.  

spike