New study simulates gravitational waves caused by warp engine failure

Imagine a spaceship powered not by engines, but by the compression of space-time in front of it. It’s the stuff of science fiction, right? Well, not entirely. Physicists have been exploring the theoretical possibility of “warp engines” for decades, and a new study published in Open Journal of Astrophysics He goes even further by simulating the gravitational waves that such an engine could emit if it failed.

Warp drives are a staple of science fiction and could in principle propel spaceships to greater than the speed of light. Unfortunately, their construction poses many problems in practice, such as the need for an exotic type of negative-energy matter.

Other problems with measuring the warp drive include the possibility of using it to create closed time curves that violate causality, and, on a more practical level, the difficulties for those aboard the ship to actually control and deactivate the bubble.

The new study is a collaboration between gravitational physicists from Queen Mary University of London, the University of Potsdam, the Max Planck Institute (MPI) for Gravitational Physics in Potsdam, and Cardiff University. While it does not claim to have cracked the code of warp drive, it explores the theoretical consequences of a “confinement failure” of warp drive using numerical simulations.

Dr Katy Clough from Queen Mary University of London, first author of the study, explains: “Although warp drives are purely theoretical, they have a well-defined description in Einstein’s theory of general relativity, and so numerical simulations allow us to explore the impact they might have on spacetime in the form of gravitational waves.”

Co-author Dr Sebastian Khan, from Cardiff University’s School of Physics and Astronomy, added: “Miguel Alcubierre created the first warp propulsion solution during his PhD at Cardiff University in 1994, and later worked at MPI Potsdam. It is therefore only natural that we continue the tradition of warp propulsion research in the era of gravitational-wave astronomy.”

The results are fascinating. The collapse of the warp drive generates a distinct burst of gravitational waves, a ripple in spacetime that could be detected by gravitational-wave detectors that normally target black hole and neutron star mergers. Unlike the hisses emitted by merging astrophysical objects, this signal would be a short, high-frequency burst, and so current detectors would not detect it.

However, future higher-frequency instruments could do this, and while none of these instruments have been funded yet, the technology to build them exists. This raises the possibility of using these signals to search for evidence of warp drive technology, even if we can’t build it ourselves.

Dr Khan cautions: “In our study, the initial shape of spacetime corresponds to the warp bubble described by Alcubierre. Although we have been able to demonstrate that an observable signal could in principle be detected by future detectors, given the speculative nature of the work, this is not sufficient to guide the development of the instrument.”

The study also looks at the energetic dynamics of warp drive collapse. The process emits a wave of negative energetic matter, followed by alternating positive and negative waves. This complex dance results in a net increase in the overall energy of the system and could in principle provide another signature of the collapse if the outgoing waves interacted with normal matter.

This research pushes the boundaries of our understanding of exotic spacetimes and gravitational waves. Professor Dietrich comments: “For me, the most important aspect of this study is the novelty of accurately modelling the dynamics of negative-energy spacetimes and the possibility of extending the techniques to physical situations that can help us better understand the evolution and origin of our universe, or avoid singularities at the centre of black holes.”

Dr Clough added: “This reminds us that theoretical ideas can push us to explore the universe in new ways. Even if we are sceptical about the likelihood of seeing anything, I think it is interesting enough to be worth investigating.”

The researchers plan to study how the signal changes with different warp patterns and explore the collapse of bubbles moving at speeds faster than light itself. Warp speed may still be a long way off, but the quest to understand the secrets of the universe continues, one simulated collision at a time.