Can a particle be somewhere else in the universe an instant from now? Feynman's own path-integral formula says yes — sort of. To calculate where a particle is likely to end up, physics sums over EVERY possible path it could take, including ones that reach beyond the edge of what light could cross in that time. Fig. 1 shows exactly this: the blue arrows are the paths that survive inside the light cone, reinforcing each other into the "classical" trajectory you'd expect. The red dotted arrows are the paths that formally exist outside it — nonzero, but so thoroughly self-cancelling that nothing you could ever measure or send a message with makes it across. That one paragraph is the seed of a new paper: "Closed Under What Theory?" — a follow-up to an earlier piece asking whether the Prophet's night journey (Isra and Mi'raj, Qur'an 17:1) could be reconciled with a universe where nothing outraces light. The short version: no particle, signal, or person is shown to travel faster than light here — that's still firmly closed. But whether that door is closed FOREVER, or just closed under today's physics, turns out to be a live question in quantum gravity research (look up "ER=EPR" if you want to fall down a real rabbit hole). Read it, argue with it, tell me where it's wrong.
Fig. 1 — Paths from A within the light cone (solid blue) dominate the surviving amplitude; paths reaching spacelike-separated points (dotted red) are formally present in the non-relativistic kernel but carry no signal and no detectable transport.
Can a particle be somewhere else in the universe an instant from now? Feynman's own path-integral formula says yes — sort of. To calculate where a particle is likely to end up, physics sums over EVERY possible path it could take, including ones that reach beyond the edge of what light could cross in that time. Fig. 1 shows exactly this: the blue arrows are the paths that survive inside the light cone, reinforcing each other into the "classical" trajectory you'd expect. The red dotted arrows are the paths that formally exist outside it — nonzero, but so thoroughly self-cancelling that nothing you could ever measure or send a message with makes it across. That one paragraph is the seed of a new paper: "Closed Under What Theory?" — a follow-up to an earlier piece asking whether the Prophet's night journey (Isra and Mi'raj, Qur'an 17:1) could be reconciled with a universe where nothing outraces light. The short version: no particle, signal, or person is shown to travel faster than light here — that's still firmly closed. But whether that door is closed FOREVER, or just closed under today's physics, turns out to be a live question in quantum gravity research (look up "ER=EPR" if you want to fall down a real rabbit hole). Read it, argue with it, tell me where it's wrong.
📖 Read paper.pdf