Imaginary Mass
A hypothetical particle with imaginary rest mass would always travel faster than the speed of light. Such particles are called tachyons. There is no confirmed existence of tachyons.
If the rest mass is imaginary this implies that the denominator is imaginary since the total energy is an observable and thus must be real; therefore the quantity under the square root must be negative, which can only happen if v is greater than c. As noted by Gregory Benford et al., among others, special relativity implies that tachyons, if they existed, could be used to communicate backwards in time (see Tachyonic antitelephone article). Since time travel is considered to be non-physical, tachyons are believed by physicists either to not exist, or else to be incapable of interacting with normal matter.
In quantum field theory, imaginary mass would induce tachyon condensation.
Read more about this topic: Exotic Matter
Famous quotes containing the words imaginary and/or mass:
“Fiction is not imagination. It is what anticipates imagination by giving it the form of reality. This is quite opposite to our own natural tendency which is to anticipate reality by imagining it, or to flee from it by idealizing it. That is why we shall never inhabit true fiction; we are condemned to the imaginary and nostalgia for the future.”
—Jean Baudrillard (b. 1929)
“Compare the history of the novel to that of rock ‘n’ roll. Both started out a minority taste, became a mass taste, and then splintered into several subgenres. Both have been the typical cultural expressions of classes and epochs. Both started out aggressively fighting for their share of attention, novels attacking the drama, the tract, and the poem, rock attacking jazz and pop and rolling over classical music.”
—W. T. Lhamon, U.S. educator, critic. “Material Differences,” Deliberate Speed: The Origins of a Cultural Style in the American 1950s, Smithsonian (1990)