Slashdot Mirror
'Halo Drive' Would Use Black Holes To Power Spaceships (space.com)
A new study from researchers at Columbia University in New York suggests future spaceships could use black holes as powerful launch pads to explore the universe. The study "envisions firing laser beams that would curve around a black hole and come back with added energy to help propel a spacecraft to near the speed of light," reports Space.com. "Astronomers could look for signs that alien civilizations are using such a 'halo drive,' as the study dubs it, by seeing if pairs of black holes are merging more often than expected." From the report: Study author David Kipping, an astrophysicist at Columbia University in New York, came up with the idea of the halo drive through what he calls "the gamer's mindset." Using what he called a "halo drive" -- named for the ring of light it would create around a black hole -- Kipping found that even spaceships with the mass of Jupiter could achieve relativistic speeds. "A civilization could exploit black holes as galactic waypoints," he wrote in a study accepted by the Journal of the British Interplanetary Society and detailed online Feb. 28 in the arXiv preprint server.
The major drawback of a halo drive would be that "one has to travel to the nearest black hole," Kipping said. "It's akin to paying a one-time toll fee to ride the highway system. You have to pay some energy to reach the nearest access point, but after that, you can ride for free as a long as you like." The halo drive works only in close proximity to a black hole, at a distance of about five to 50 times the black hole's diameter. "This is why you have to travel to the nearest black hole first and [why you] can't simply do this across light-years of space," Kipping said. "We still first require a means to travel to nearby stars to ride the highway system. Kipping is now investigating ways to exploit other astronomical systems for relativistic flight. Such techniques "may not be quite as efficient or fast as the halo-drive approach, but these systems possess the deep energy reserves needed for these journeys," Kipping said.
The major drawback of a halo drive would be that "one has to travel to the nearest black hole," Kipping said. "It's akin to paying a one-time toll fee to ride the highway system. You have to pay some energy to reach the nearest access point, but after that, you can ride for free as a long as you like." The halo drive works only in close proximity to a black hole, at a distance of about five to 50 times the black hole's diameter. "This is why you have to travel to the nearest black hole first and [why you] can't simply do this across light-years of space," Kipping said. "We still first require a means to travel to nearby stars to ride the highway system. Kipping is now investigating ways to exploit other astronomical systems for relativistic flight. Such techniques "may not be quite as efficient or fast as the halo-drive approach, but these systems possess the deep energy reserves needed for these journeys," Kipping said.
And it would take a lot of energy to make one
I bet that by the time we'd be able to make this idea work, we will have found a better one.
Small thinking mistake in this hypothesis,... Which life forms - or complex matter of any kind - is able to survive the gravitational pull at a distance of only 50 times the radius of a black hole?
That close to a black hole you get fantastic time dilation. After you move away, you find your whole civilization gone, or changed to something new.
I don't think your hostility is warranted...
Firstly, we have no evidence that it's not possible to fold space to make wormholes, but we do have a pile of evidence that it might be possible, in the form of the mathematical models that keep getting tested and shown to actually match the way the real universe behaves. There have been plenty of experiments that take a form like "according to those models, if we find this object with X and Y parameters, it should also have Z", and when we actually stumble across an object matching those parameters, the model is confirmed at those parameters.
The speculative (not "fiction") part comes when we start looking at the edge cases of those models. What if we had a black hole that was extremely low mass, and compressed with forces stronger than gravity? What if its particles were entangled with those in another black hole? What if multiple black holes are arranged to produce a particular spacetime curvature to amplify other relativistic effects like time dilation?
For cases like those, the math works out, and shows weird results that we haven't observed in the physical world. That doesn't mean they aren't possible, but just might not be natural in conditions seen since the Big Bang. As humans, though, we excel at creating unnatural conditions. We can synthesize large quantities of unstable atoms, and trigger their decay with extreme precision. We can focus lasers to target single molecules. We can create beams of entangled particles and send them to locations a thousand kilometers apart, with enough surviving to perform further experiments.
Perhaps some day, we'll be able to engineer a way to directly test those edge cases in our models. Until then, they remain as open questions, best described as "apparently possible".
Now, as for your example...
Go ahead and wave your arms over your head. You've just warped spacetime, in a tiny and (for human technology at this time) immeasurable way. A record of your action is spreading out into the universe in the form of a gravitational wave, showing a slight shift in the position of your arm's mass. It took very little energy to move your arm, but you've actually deformed spacetime.
All of the physics involved in the preceding paragraph are measured and well-tested. Those tests allow us to gauge the scale of universal processes. It takes very little work to warp spacetime... literally just existing will do it. According to our models, though, we'd need a huge amount of deformation to create something like a wormhole. Multiply those scales together, and you end up with a problem on the larger side of "reasonable". It'll take energy levels somewhere between a nuclear bomb and a star (because estimates like this aren't exactly precise), but it's something humans could feasibly test before our extinction.
Once that test happens, one of two results will follow. Either we will have wormhole-creation technology and can go exploring the universe with wormholes as a tool, or we will have an observation that breaks our predicted models, and we'll have to create a new model that accounts for all of our observations. Either way, it'll be an exciting day for physicists.
You do not have a moral or legal right to do absolutely anything you want.