The Enterprise’s warp engine, which makes the ship go faster than light, could be built much sooner than we thought. Or at least that’s what a team of researchers from the Applied Physics group, which advises governments and companies on scientific and technological issues, thinks based on a paper they just published in the journal “Classical and Quantum Gravity.”
In their study, the researchers openly say that they have made the first workable model of a curvature motor. This model is based on an idea that Mexican physicist Miguel Alcubierre had more than 20 years ago, and Alcubierre has backed the research.
“Many people in the field of science” – says Alexey Bobrick, first author of the article – “are familiar with Alcubierre’s motor and believe that bending impulses are not possible in the physical world due to the need to use negative energy. But this, however, is no longer the case.”
The Alcubierre engine, which was where it all began
In the same magazine (Classical and Quantum Gravity) in 1994, Miguel Alcubierre came up with a clever way to solve the equations of the General Theory of Relativity. Since then, his idea has been called “Alcubierre’s metric.” It meant that a spaceship could travel at more than 300,000 km/s, or faster than light, without breaking any physical laws.
Alcubierre suggested that the ship go through a space-time warp bubble to do this. Behind the ship, spacetime would get bigger, which would push the bubble, while in front of it, spacetime would get smaller, which would bring the target closer and closer. Inside the bubble, the ship would stay still in a flat (not warped) space, so it wouldn’t break the law that says you can’t go faster than light. It would be like a person standing still on a full-speed-ahead moving conveyor belt.
The picture shows a space-time warp bubble inside of which a ship would stay in flat space (yellow). The bubble would make the space behind the ship bigger and the space in front of the ship smaller, letting the ship go very fast. – Gianni Martire (Applied Physics)
In fact, Alcubierre’s ship would be moved by the bubble at speeds faster than light, but it would be space, not the ship, that would “move” as the bubble expanded and shrank over and over again. In practice, relativity says that nothing can move through spacetime faster than light, but it doesn’t say anything about how fast spacetime itself can go. So, Alcubierre’s idea was a great first step toward the famous “bending motor” from the “Star Trek” series, which, by the way, inspired his work.
The problem is that in order to make the space-time deformation bubble that gives the push, matter with negative or exotic density would have to be used to get negative energy, which does not exist. Because of this, the Alcubierre engine is completely out of our reach. The speed at which the bubble spreads would easily be faster than the speed of light the more negative energy there is in it.
Because of these problems, physicists had long since given up on Alcubierre’s idea for an engine, and most people thought that space-time warping would never be used to make engines. Researchers say that since 2012, NASA has been trying to design physical deformation units at the Eagleworks laboratories at the Johnson Space Center in Houston, Texas, but has not been able to do so.
A solution without negative energy
But the new study has managed to avoid that problem. In Bobrick’s words: “We went in a different direction than NASA and other researchers. Our research has shown that there are actually several more types of bending momentum in General Relativity . In particular, we have formulated new classes of curvature impulse solutions that do not require negative energy and therefore can occur in the physical world.”
Giving up the negative energy that Alcubierre suggests would slow things down, though. The researchers’ idea for a curvature motor is, in effect, “subluminal” and, at least in theory, can be built using physical laws that are known to people today. It can’t go faster than light, but it’s very close,” the researchers write.
In any case, they add, “We have shown that all the criticisms of Alcubierre’s famous motor are irrelevant because there is a whole variety of other units of curvature that are physical, and that can be used. Therefore, the Applied Physics team has shown that bending field mechanics is not dead before birth, but is a viable physical science.”