Alcubierre Warp Drive
Spaceship Engine Future
Few find such science-fiction novels about travel in Space, where the starship would not have been equipped with a "hyperspace engine." For obvious reasons, details of the device and its authors do not fall, but a quick view of classics revealed that the engine somehow bend space so that distant stars are close and can reach up to them for a couple of hours. Until recently it was believed that such stunts are incompatible with the fundamental laws of physics, but now it seems everything is changing.
In the May issue of the 1994 scientific journal "Classical and Quantum Gravity" English physicist Spanish origin Miguel Alkuberre (himself, in his admittedly a big fan of fiction) described the principle of excess speed flight, strongly reminiscent of fabrications fiction. Realized it in practice, can be arbitrarily quickly get anywhere in the universe.
Creating an engine Alkuberre become possible thanks to some subtleties of Einstein's general theory of relativity, According to Einstein, prostranstvovremya ( "fusion" three dimensions of space with the fourth dimension - time) is not inert, but rather a dynamic entity. Under the influence of concentrations of energy compressed space and time can bend. As Alkuberre suggests, is his property can be used for interstellar flight at speeds above the speed of light. It's enough to create spacetime in such a breach, in which it will be before starshhip compressed, and behind him to expand. Such a distortion would actually push forward starship. He incur forward, as board surfing on the crest of a wave bears.
At first glance, such a conclusion contradicts the special theory of relativity, on which nothing tangible can not move faster than light. Otherwise one would paradox of causality, in which people could change their past. But Alkuberre confident that his engine did not lead to such violations. The problem is that light is also moving in spacetime, and this spacetime, it also carries forward, as it bears the ship. In relation to ship the light beam continues to fly at the speed of light, but no ship is accelerating in relation to the section of the spacetime, which immediately surrounds it.
While the engine Alkuberre, according to the author's ideas, does not lead to a breach of the principle of causality, may still be a concern for the health of pilots and passengers of the ship. For a few moments to get a distant star and come back, travelers would have to undergo a very large acceleration, which would inevitably Has smeared on their walls. But remember that in the general theory of relativity regarding the acceleration. Although the observer on Earth will accelerate such a huge ship, for space travelers themselves, it would be zero! Travelers will stay while in weightlessness as astronauts in Earth orbit.
Finally, Alkuberre proves that traveling to his spacecraft did not undergo stretching time. According to one of the consequences of Einstein's special theory of relativity, time flows at different rates for observers moving relative to one another. Consider two astronauts, A and B, leaving Nebula in Andromeda - a huge galaxy, a remote about two million light-years from us, Astronaut A flies to Alkuberre starship engine, and V astronaut - on old-fashioned starship, which will be all the way to develop acceleration, equal around the acceleration of gravity. Speed In almost all the way around would-light. Because of time stretching astronaut survive in the entire flight, aged for 60 years. But because the galaxy removed from the Earth at 2 million light-years, the Earth during this time will be more than 4 million years! Astronaut A has done all the way there and back in one day, breakfast and dinner on Earth.
What are lacking to create a wonderful engine? The most smallness - the so-called exotic matter. The same, yet only theoretically sound, but never observed in nature and substance needed to create a time machine (see "Science and Life" № 2, 1990). Exotic matter, unlike normal, around us and not bad education in physics, has a negative energy density, the bodies of two ordinary matter, with the energy density equal the mark, attracted to one another by force of gravity, Just behave and two bodies of exotic matter. A two bodies of matter with different signs energy density will build one from another. That negative energy density of matter and exotic driven starship (returning to fiction, remember that in one of the novels interstellar ships used as a fuel anamezon; whether this is not the exotic matter?).
The figure, performed by Miguel Alkuberre, shown outrage
space-time, which will create its engine. At the crest of this
perturbations ship moving in the direction of the arrow. Before
Space shuttle compressed, making available the most distant
stars behind the rise, claiming the ship further from Earth.
But whether that is possible - negative energy density? The possibility of the existence of substance with such properties predicted back in 1948, the Dutch physicist Hendrik Casimir. He calculated that if the negative energy density possible, the two parallel plates of conducting material placed in a vacuum, should be slightly attracted to each other in 1958, this phenomenon was discovered in the laboratory and called the Casimir effect. The possibility of the existence of exotic matter is provided for in the modern theory of the universe expanding.
However, before the start of hyperspace build spacecraft, will have beds to allow such technical difficulties. For example, as developed or find large quantities of this most exotic matter? But Alkuberre no such policy is no longer interested in the details, he gives them to other physicists and engineers, and the problems now embarked on the general theory of relativity.