3 ms·

..I was under the impression that special relativity only forbade accelerating to the speed of light - particles that always traveled FTL (i.e. tachyons) were e

• andyjohnson0 14y ago
  That was my understanding too. Although its worth noting that the existence of Tachyons is entirely speculative.
• stargazer-3 14y ago
  Tachyons have complex mass, for one thing. The authors described the way to move between frames of reference of superluminal particles, so that they (particles) seem to have real finite physical properties. At least that's my understanding.
  • cygx 14y ago
    There are two different concepts of tachyons: Quantum fields with imaginary mass and faster-than-light particles. Tachyonic fields still (anti)commute at space-like separation, which preserves causality. Such fields are maximally unstable and do not permit a particle picture. They are used to describe spontaneous symmetry breaking. Tachyonic particles are a concept from special relativity. While one can also attribute an imaginary mass to such particles, this basically encodes a sign convention. These theoretical particles exhibit some perculiar properties (zero-energy particles which travel at infinite velocity and finite momentum, different observers will disagree on emitter and absorber - in fact, during a tachyonic interaction, both endpoints may claim to be emitter or absorber in their respective rest frames depending on their relative motion, ...). According to Recami[1], no causal paradoxa occur. [1] http://dinamico2.unibg.it/recami/erasmo%20docs/SomeRecentSCIENTIFICpapers/ExtendedRelativity/TachyonCausalParadoxesSOLVED.pdf http://dinamico2.unibg.it/recami/erasmo%20docs/SomeRecentSCI...