There Are No Useful Wormholes

4gravitons reports from Strings 2018 on one of the less controversial points at the Conference (his reference to "from these talks" is to one afternoon of the Conference, not the Conference overall):

My main takeaway from these talks was perhaps a bit frivolous: between Maldacena’s talk (about an extremely small wormhole made from Standard Model-compatible building blocks) and Hartman’s discussion of the Average Null Energy Condition, it looks like a “useful sci-fi wormhole” (specifically, one that gets you there faster than going the normal way) has been conclusively ruled out in quantum field theory.

This is unfortunate, as this is a staple of science fiction writing, which now can't really be claimed to have even a speculative basis.