On the impossibility of superluminal travel: the warp drive lesson

TL;DR

This paper examines the theoretical feasibility of warp drives for superluminal travel, demonstrating that quantum effects inevitably destabilize such spacetime structures at superluminal speeds, reinforcing the light speed limit.

Contribution

It provides a quantum back-reaction analysis showing warp drives cannot remain stable at superluminal speeds, supporting the impossibility of faster-than-light travel.

Findings

Quantum back-reaction destabilizes warp drives at superluminal speeds

Warp drive geometries cannot survive quantum effects when accelerated beyond light speed

Supports the fundamental speed limit imposed by relativity

Abstract

The question of whether it is possible or not to surpass the speed of light is already centennial. The special theory of relativity took the existence of a speed limit as a principle, the light postulate, which has proven to be enormously predictive. Here we discuss some of its twists and turns when general relativity and quantum mechanics come into play. In particular, we discuss one of the most interesting proposals for faster than light travel: warp drives. Even if one succeeded in creating such spacetime structures, it would be still necessary to check whether they would survive to the switching on of quantum matter effects. Here, we show that the quantum back-reaction to warp-drive geometries, created out of an initially flat spacetime, inevitably lead to their destabilization whenever superluminal speeds are attained. We close this investigation speculating the possible significance of this further success of the speed of light postulate.