“Final one: anything launched by a railgun (if you could ever reach ~ Mach 27) would explode upon exi…”

“Ion thrusters are great, but have extremely tiny force (photon thruster even less). Must have more t…”

“And pls don't ask me about space elevators until someone at least builds a carbon nanotube structure…”

“Reason is Newton's Third Law. In vacuum, there is nothing to "push" against. You must react against …”