Traveling at superluminal speeds, that is, more than 300,000 km / s, is now science fiction. However, there is a theory that suggests the feasibility of such a trip. This came in part thanks to the Star Trek franchise. According to SF, there are only two ways to move faster than light: hyperspace and distortion.
The warp motor is particularly popular in the saga of American writer and screenwriter Eugene Wesley Roddenberry in the 1960s. This prompted the physicist Miguel Alcubierre to develop mathematical formulas in 1994 that theoretically make this drive compatible at least with Einstein’s theory of relativity. And that’s called the Alcubierre metric.
A wave in spacetime
It should be noted that Alcubierre’s Metric has a different interpretation of the concept of supraluminal travel. The theory is not based on the actual acceleration of the spacecraft. Rather, it consists of creating an energy field around you that can bend space-time. Specifically, the space behind the device expands while the front one contracts and creates a kind of wave in spacetime.
This would move the ship a bit like a surfboard. The concept suggests that the vehicle is not advancing at the speed of light. It moves in a kind of bubble and the superluminal velocity is achieved thanks to the contraction of space-time.
Negative mass energy, an important element
Of course, Alcubierre’s metric does not violate any law of physics, but it has a flaw. This theory effectively states that it is necessary to use negative mass energy in order to bend space-time and thus move at a speed greater than that of light. In other words, an energy whose density is less than a vacuum.
Bend space-time and move at a speed that is greater than that of light (artist’s illustration). Image Credit: Shutterstock / Space Creator
This source of positive / negative energy would behave like a difference in positive / negative electrical charge. The distortion of spacetime would thus be made possible by the contrast between the positive mass (behind the vessel) and the negative mass (in front of the vessel). Even so, the idea of a negative mass, although already considered by Einstein, remains a mere hypothesis so far.
A job that could change the game
To overcome the obstacle created by the negative mass, an international team of physicists called Applied Physics focused on the question and created new formulas. These relate to spatio-temporal distortions that do not require such a mass. Compared to the statements of Miguel Alcubierre, they would be closer to reality and would make traveling at super light speed physically possible.
However, in their publication in the journal Classical and Quantum Gravity earlier this year, the authors acknowledge that the mass requirements in the models they have developed are far from being tested with current technologies. While traveling at the speed of light is impossible in the short to medium term, her work represents a major breakthrough for her that could one day play a pivotal role.