Wormhole + black hole = time machine #tibees

wormholes excite us as shortcuts through space, but in a special case they could also be shortcuts through time. Einstein's equations showed that mass has an impact on the space and time around it. A black hole is an intense concentration of mass and would distort the space and time around itself so much that time slows to a stop at the horizon of the black hole. If we got lucky and found a wormhole that had its other end near a black hole, then traveling through it would split us out in the past to a region where time runs slower than back home. In theory, a very clever version of our future selves might be able to tie one end of a wormhole to a spaceship and take it wherever they wanted, but right now we can't manipulate space time in this way, and the existence of wormholes is pretty shaky at best.