Warp drive, i.e., a thruster operating on the principle of warp space fictionalized by sci-fi writers. However, the general theory of relativity quite admits its existence. Recently, scientists have proved that its operation far out in space can be detected due to the gravitational waves it emits.
What is a warp drive and is it possible to create one?
The sci-fi saga Star Trek gave the world the concept of warp drive. It is related to the fact that nothing in physical space can move faster than light. However, if you warp space around a spacecraft, it can actually exceed the speed of light while technically staying within its limits.
Sounds fantastic, but back in 1994, Mexican physicist Miguel Alcubierre proved that this was quite possible within the framework of the general theory of relativity. At least it does not explicitly prohibit its existence, although there are a whole bunch of physical and technical obstacles to its realization.
The main obstacle to the realization of warp drive, or as it is called the Alcubierre Drive, needs to reach a state of zero energy. Physics explicitly forbids situations where some part of space has its negative density, but there are several workarounds that can overcome this limitation. However, physicists can’t say which of them can actually be realized.
Another problem with the Alcubierre Drive is that after the space bubble is created, communication on the spacecraft will be impossible and the crew will have no way to control it. In addition, physicists cannot yet find a stable equation of state for this device. That is, the region of warped space is doomed to collapse.
Gravitational waves
But despite this scientists at least know that warp drive is possible and it is worth looking for traces of its use by other civilizations. A new theoretical paper focuses on how to do this. It turned out that the Alcubierre Drive cannot be detected only when it is stable.
But at the collapse of a spatial bubble gravitational waves should be born, similar to those which are born at merger of neutron stars or black holes. Their frequency is well within the range available to our detectors. So we can track an alien ship if its engine suddenly shuts down.
Scientists can even predict what such a signal should look like. And it is indeed different from the gravitational waves we pick up from merging black holes and neutron stars. That is, it won’t be a problem to recognize it either.
According to phys.org
