Future spacecraft could use black holes as powerful launching pads for studying stars
A new study involves firing laser beams that bend over a black hole and return with extra energy to help propel a spacecraft to the speed of light. Astronomers could look for signs that alien civilizations use such a "halo-drive," as the study calls it, seeing if the pair of black holes merge more than expected.
David Kippin, an astrophysicist at Columbia University in New York, has come up with an idea of the halo that he calls "gamer thinking."
Listed: The vision of the Interstellar Star Travel (Gallery)
"Sometimes in a computer game you find" exploit ", that's a hack that allows you to do something defeated that would otherwise be prohibited by the rules of the game ", ̵
A key challenge to using rockets to fly through space is that the fuel they bring with them has a mass. Long trips require a lot of fuel, which makes heavy rockets, which in turn requires more fuel, making the rockets even harder and so on. This problem becomes exponentially worse, the more a missile gets. Instead of wearing a propellant for motion, a spacecraft equipped with mirror sails could rely on lasers to push them out. The $ 100 Million Initiative Breakthrough Starshot announced in 2016, plans to use powerful lasers to promote spacecraft roar to the Alpha Centauri, the nearest star system to our own, up to 20 percent of the speed of light. 19659002] A spacecraft trying to launch Breakthrough Starshot, each with a microchip size only. In order to accelerate large spacecraft to relativistic velocities – to a significant proportion of the speed of light – Kipping sought gravity assistance.
The spacecraft now regularly uses "slingshot maneuvers", in which the body weight, for example, the planet or the Moon, throws ships through the space and raises their speed. In 1963, a well-known physicist, Freeman Dyson, suggested that spacecraft of any size can rely on the slingshots maneuver around compact pairs of white dwarfs or neutron stars to fly at relativistic speeds. (Dyson came up with an idea of what became known as the sphere Dyson of a mega structure that encapsulates a star to capture as much of its energy as possible to transform a developed civilization.)
"Dyson's throat" may damage the spacecraft because of extreme gravity and dangerous radiation from these pairs of dead stars. Instead, Kippin emphasizes that gravity can help spacecraft by increasing the energy of laser beams emitted along the edges of black holes
. Their gravitational fields can also distort paths of photons of light that do not fall into the openings.
In 1993, physicist Mark Styuki suggested that a black hole could, in principle, act as a "gravitational mirror", since the Black Hole gravity could disperse the photon around so that it returned to its source. Kipping calculated that if a black hole moves to a photon source, then the "photon boomerang" will push off part of the energy of the black hole.
Listed: No escape: plunge into a black hole (Infographic)
Using what he called the "halo-drive" – named after the ring of light, he would have created around a black hole – Kipping found that even the spacecraft with mass of Jupiter could achieve relativistic velocities. "Civilization could use black holes as galactic paths," he wrote in a study adopted by the British Interplanetary Society magazine, and published in detail on February 28 at the server of the arXiv preprint
. the black hole moves, the more energy the drive halo can extract from it. Thus, Kippin largely focused on the use of pairs of black holes that spiraled to each other before the merger.
Astronomers could look for signs that other civilizations exploit a pair of black holes for travel with such an engine. For example, halo drives will effectively steal energy from such binary black hole systems increasing the speed of merging pairs of black holes above what one would expect from nature, said Kippin. His results were based on accelerations from the pairs of black holes rotating around each other at relativistic velocities. Although there are approximately 10 million pairs of black holes in the Milky Way, Kipping noticed that few of those who rolled in orbit for a long time at relativistic speeds, as they merge rather quickly.
However, he noted that isolated, rotating black holes can also run halo drives at relativistic speeds, "and we already know numerous examples of relativistic, rotating supermassive black holes."
The main disadvantage of the halo is that "it is necessary to go to the nearest black hole," said Kipping. "It's like paying a one-time toll on the highway, you have to pay a bit of energy to get to the nearest access point, but after that you can ride for free for as long as you like."
The halo drive works only in the immediate proximity of the black hole, at a distance from about 50 to 60 in the diameter of the black hole. "That's why you have to go to the nearest black hole, and [why you] can not just do it through the light years of space," said Kipping. "We still need money first to go to neighboring stars to drive along the highway."
"If we want to achieve a relativistic flight, then it requires huge energy levels, regardless of which power system you use," – added he is bypassing this – to use astronomical objects as an energy source, since they have literally astronomical energy levels within them. In this case, the binary with black holes is, in essence, a gigantic battery awaiting us to push it. The idea is that work with nature, not against it. "
Kipping is now exploring ways of exploitation of other astronomical systems for relativistic flight. Such methods "may not be as effective or quick as a halo-driven approach, but these Systems have the deep reserves of energy needed for these trips," Kipping said.
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