>>12799134>the craft itself doesn't go faster than light, tard, space warps around it. it's literally in the name. stop making popular mechanics look goodI know how it works you fucking idiot. You draw a large sphere, and make the spatial metric components inside the sphere small, so that material inside the sphere can travel at locally sub-luminal speed, and yet go faster than light relative to infinity. Then move the sphere with the same speed as the sub-luminal thing inside. You can make up any geometry, and then use Einstein's equations backwards to find the stress and matter required. It doesn't matter if you're locally going less than FTL, you are still going FTL globally. Faster than light travel in an asymptotically flat background (in a space that looks like ordinary 4-dimensional Minkowski space at infinity) allows you to go back in time, simply by travelling faster than light in one frame, and returning to your starting point in a booted frame (this is a standard special-relativity construction). So it is not possible to travel faster than light even in GR, because matter is constrained to the null-energy condition, or equivalently, you can't go back in time.
