Examples of apparent FTL proposals are the Alcubierre drive, Krasnikov tubes, traversable wormholes, and quantum tunneling.
Apparent FTL is not excluded by general relativity however, any apparent FTL physical plausibility is currently speculative. "Apparent" or "effective" FTL, on the other hand, depends on the hypothesis that unusually distorted regions of spacetime might permit matter to reach distant locations in less time than light could in normal ("undistorted") spacetime.Īs of the 21st century, according to current scientific theories, matter is required to travel at slower-than-light (also STL or subluminal) speed with respect to the locally distorted spacetime region. Particles whose speed exceeds that of light ( tachyons) have been hypothesized, but their existence would violate causality, and the consensus of physicists is that they do not exist, and their existence would imply time travel. The special theory of relativity implies that only particles with zero rest mass (i.e., photons) may travel at the speed of light, and that nothing may travel faster. Nature 331, 147–149 (1988).Spacetime diagram showing that moving faster than light implies time travel in the context of special relativityįaster-than-light (also FTL, superluminal or supercausal) travel and communication are the conjectural propagation of matter or information faster than the speed of light ( c).
Because different components emerge with different velocities 7,8, a third epoch of observations is needed to determine if any deceleration has occurred. Comparison with an earlier image shows that superluminal motion extends out to at least 120 pc, three times farther than previously noted 7. The jet extends out to 220 pc, and some models 5,6 require that the relativistic bulk flow should continue along its entire length.
We fail to see a counter-jet, a result which is just barely consistent with the standard model of a superluminal jet. We have made observations at 1.7 GHz, using very-long-baseline interferometry with a global network of 16 radiotelescopes, resulting in a high-dynamic-range map of the jet with a ratio of peak brightness to r.m.s. The same explanation allows an intrinsically similar 'counter-jet', moving at high speed in the opposite direction, to be dimmed to invisibility. It was also the first object to display apparent superluminal motion on parsec scales 2, a phenomenon attributed to relativistic effects on the appearance of a jet moving close to the line of sight 3,4.
THE quasar 3C273, one of the first discovered 1, is optically the brightest example of a source with a one-sided jet.
0 kommentar(er)
