The idea of a chain drive that takes us across large areas of space faster than the speed of light has long fascinated both scientists and sci-fi fans. While we are still very far from jumping over universal speed limits, that does not mean we will never ride the waves of the crooked space-time.
Now a group of physicists has put together the first proposal for a physical chain drive, based on a concept that was devised back in the 90s. And they say it should not break any of the laws of physics.
Theoretically, chain drives bend and change the shape of spacetime to exaggerate differences in time and distance that, in some circumstances, could see travelers moving over distances faster than the speed of light.
One of these circumstances was outlined more than a quarter of a century ago by the Mexican theoretical physicist Miguel Alcubierre. His idea, proposed in 1
But the new study has a solution. According to researchers from the independent research group Applied Physics, based in New York, it is possible to remove the poems about negative energy and still make a chain drive, albeit one that may be a little slower than we would like.
“We went in a different direction than NASA and others, and our research has shown that there are actually several other classes of chain drives in general relativity,” says astrophysicist Alexey Bobrick from Lund University in Sweden.
“In particular, we have formulated new classes of chain drive solutions that do not require negative energy and thus become physical.”
Why is negative energy so much? The need for negative energy solves some of the general problems of relativity at faster than light travel by allowing space to expand and contract faster than light, while keeping everything within its rotation within universal speed limits.
Unfortunately, it introduces several problems of its own – primarily that the negative energy we need is only found in fluctuations on a quantum scale. Until we can find a way to get a solar size of things, this kind of drive is just not possible.
The new research works around this – according to the paper, negative energy would not be required, but an enormously powerful gravitational field would be. Gravity would make the heavy lifting of bending space time so that the time course inside and outside the chain drive machine would be significantly different.
However, you can not reserve tickets yet – the amount of mass required to produce a noticeable gravitational effect in space-time would be at least planet size, and there are still plenty of questions to answer.
“If we take the mass of the entire planet Earth and compress it into a shell with a size of 10 meters, then the correction to the time velocity inside it is still very small, almost an extra hour a year,” Bobrick told New scientist.
Another interesting finding from the research concerns the shape of the chain drive: a wider, taller vessel needs less energy than a long and thin one. Think of a plate that is held vertically, thrown against a wall surface first, and you have an idea of the optimal chain shape.
Although the reality of traveling to distant stars and planets is still far away, the new study is the latest addition to a growing body of research suggesting that the principles of chain drives are sound in scientific terms.
The researchers admit that they are still not quite sure how to put together the technology that they have described in their paper, but at least more of the numbers are being added now. They are convinced that the chain drive well into the future will become a reality.
“Although we still cannot break the speed of light, we do not need it to become an interstellar species,” said Gianni Martire, one of the researchers at the applied physics group behind the new study. “Our chain research has the potential to unite us all.”
The research is published in Classical and quantum gravity.