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:
“We do not content ourselves with the life we have in ourselves and in our being; we desire to live an imaginary life in the mind of others, and for this purpose we endeavor to shine. We labor unceasingly to adorn and preserve this imaginary existence and neglect the real.”
—Blaise Pascal (1623–1662)
“The pathetic thing about the great wellintentioned mass of college and highschool students is that they have been so badly educated they have no knowledge or understanding of the complications of the world we live in and they have been so conditioned and prejudiced by generations of ill-taught teachers that they refuse to see a fact when they are confronted with one.”
—John Dos Passos (1896–1970)