&gt; Someone had a nice explanation of this over on Reddit but I don&#x27;t have a link handy. Basically if momentum is not conserved then you can build kinetic energy without bound on finite power or something like that.<p>Are you referring to this reddit comment by myself?<p><a href="https:&#x2F;&#x2F;reddit.com&#x2F;r&#x2F;spaceflight&#x2F;comments&#x2F;34ay1c&#x2F;nasa_researchers_confirm_enigmatic_emdrive&#x2F;cqt83lg" rel="nofollow">https:&#x2F;&#x2F;reddit.com&#x2F;r&#x2F;spaceflight&#x2F;comments&#x2F;34ay1c&#x2F;nasa_resear...</a>