>The launch cost of launching the mass of the pyramids of gaza into orbit would bankrupt the richest economies. No your hypothetical engine won't be 100% effici

>The launch cost of launching the mass of the pyramids of gaza into orbit would bankrupt the richest economies. No your hypothetical engine won't be 100% efficient. This is completely unfeasible. Not necessarily. You don't need to launch the mass of the pyramids from Earth, you just need to find a source of fuel somewhere else in the Solar System that's in a shallower gravity well, like on the Moon. This is why a lot of people want to work on mining asteroids, and building mining/refining/manufacturing infrastructure offworld.