Aki Posted March 13, 2005 Report Posted March 13, 2005 If tachyons can travel faster than the speed of light, what would be its mass? Would it have a negative mass?
paultrr Posted March 13, 2005 Report Posted March 13, 2005 A tachyon (from the Greek ταχύς {takhús}, meaning "swift") is a hypothetical particle that travels at superluminal velocity. The first theoretical description of tachyons is attributed to physicist Arnold Sommerfeld; however, the concept has recurred in a variety of other contexts, such as string theory. Dr George Sudarshan is considered to be one of the early progenitors of much of tachyon theory. In the language of special relativity, a tachyon is a particle with space-like four-momentum and imaginary proper time. A tachyon is constrained to the space-like portion of the energy-momentum graph. Therefore, it can never slow to light speed or below. A tachyon is a particle with space-like four-momentum. If its energy and momentum are real, its rest mass is imaginary. It is difficult to interpret exactly what a complex-valued mass may physically mean. One curious effect is that, unlike ordinary particles, the speed of a tachyon increases as its energy decreases. This is a consequence of special relativity because the tachyon, in theory, has a negative squared mass. According to Einstein, the total energy of a particle contains a contribution from the rest mass and a contribution from the body's motion, the kinetic energy. If the Lorentz equations on this energy is correct for tachyons and regular particles then in essence their mass should be negative.
paultrr Posted March 13, 2005 Report Posted March 13, 2005 The existence of such particles would pose problems in modern physics. For example, taking the formalisms of electromagnetic radiation and supposing a tachyon had an electric charge then an accelerating tachyon must radiate electromagnetic waves, just like ordinary charged particles do. However, as we have seen, reducing a tachyon's energy increases its speed, and so in this regime a small acceleration would produce a larger one, leading to a run-away effect similar to an ultraviolet catastrophe.This has also been the simular result when it comes to string theory and such states. They tend to result in runaway inflation. There is however, the possibility of a tachyon with a real mass. In 1973, Philip Crough and Roger Clay reported a superluminal particle apparently produced in a cosmic ray shower (an observation which has not been confirmed or repeated)[1]. This possibility has prompted some to propose that each particle in space has its own relative timeline, allowing particles to travel back in time without violating causality. Under this model, such a particle would be a "tachyon" by virtue of its apparent superluminal velocity, even though its rest mass is a real number. This is actual simular to something I proposed and others have about more than one frame of reference though all the models used under such tend to differ. Some in fact can display FTL motion and forward time where the frame becomes one with a higher local speed of light to begin with. To get a picture of such think of a universe where everything here happened much faster there. These would all be cases of such a particle having real positive mass. REFERENCE 1.] Gonzales-Mestres, L. "Properties of a Possible Class of Particles Able to Travel Faster than Light." In 30th Rencontre de Moriond: Dark Matter in Cosmology, Clocks and Tests of Fundamental Laws, Villars sur Ollon, Suécia; 21-28 Jan. 1995. pp. 645-650, 1996. http://xxx.lanl.gov/abs/astro-ph/95095117/ Gonzalez-Mestres, L. "Physical and Cosmological Implications of a Possible Class of Particles Able to Travel Faster than Light" 25 Oct 1996. http://xxx.lanl.gov/abs/hep-ph/9610474/. Gonzalez-Mestres, L. "Lorentz Symmetry Violation at Planck Scale, Cosmology and Superluminal Particles." In International Workshop on Particle Physics and the Early Universe: COSMO '97, Ambleside, UK, 15-19 Sept. 1997. 1998.
paultrr Posted March 13, 2005 Report Posted March 13, 2005 For further reference on the positive mass issue and more than one frame of reference see the following Cern documents: Why Hyperspace and a Two Reference Frame System? / Hoiland, PIn a short discussion with references and author notes I discussewhy hyperspace and a two frame system makes practicle sense. [...]EXT-2004-120; Dallas Texas : Transtator Industries, 22 Sep 2004 . -4 p Why Quantum Theory does not fit observational data / Hoiland, PIts well known that quantum predictions on the energy of the vacuumor zero point field are some 120 powers bigger than whatobservational and experimental evidence show it to be. [...]EXT-2004-116; Dallas, Texas : Transtator Industries, 19 Sep 2004 . -1 p Implications of the Dutch Equation Modified PV Model / Hoiland, PIn a short outline I give some of the implications of the Dutchequation modified PV model. [...]EXT-2004-115; Dallas, Texas : Transtator Industries, 21 Sep 2004 . -2 p The Tate Anomally in the Mass of Cooper Pairs of RotatingSuperconductors from the point of view of the Higher DimensionalSpacetime defined in function of the Dutch Equation for theMacroscopic Spacetime Shortcuts in the Manyfold Universe / Loup , FWe use the Higher Dimensional Spacetime of the Manyfold Universe(asis our previous works) and Dark Matter to explain the Tate Anomallyobserved when measuring the mass of Cooper Pairs of RotatingSuperconductors as a proof that Quantum Materials are not tied to$3+1$ Spacetime according to Matos-Tajmar studies. [...]EXT-2004-138; Portugal 12 Oct 2004 . - 8 p From Planck Size to Macroscopical Size:The Dutch Equation Under TheConcept Of The Macroscopic Spacetime Shortcuts In The ManyfoldUniverse / Loup, FAccording to some authors,the presence of Dark Matter in theUniverse can only be explained by the Manyfold Universe Model usingExtra Dimensions. [...]EXT-2004-137; Portugal 07 Oct 2004 . - 7 p Variable Light Speed Cosmology(VSL) for the Kalbermann-Halevi AnsatzUnder The Concept Of The Macroscopic Spacetime Shortcuts In TheManyfold Universe / Loup, FWe present the Manyfold Universe as the unique scientificexplanation for the Mistery of Dark Matter. [...]EXT-2004-100; Portugal 21 Aug 2004 . - 7 p A More Concise formalism for Kalbermann-Halevi ansatz forMacroscopic Spacetime Shortcuts in the Manyfold Universe / Loup, FWe present the argument that the geometrical beauty of the ADDKManyfold Universe is enough to exclude the "exotic" forms of "DarkMatter" predicted by some physical theories but never observedexperimentally. [...]EXT-2004-092; Portugal 30 Jul 2004 . - 10 p Macroscopic Spacetime Shortcuts in the Manyfold Universe / Loup, FRecently the idea of a Manyfold Universe was proposed by someauthors to explain Dark Matter . [...]EXT-2004-052; Portugal 13 May 2004 . - 13 p
Aki Posted March 14, 2005 Author Report Posted March 14, 2005 Thank you paultrr for taking the time to answer my question:)
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