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Point 19 seems to conflate quantum fields with imaginary mass and superluminal particles. As far as I know, tachyonic quantum fields and tachyonic 'particles' a
by cygx 12y ago
Point 19 seems to conflate quantum fields with imaginary mass and superluminal particles. As far as I know, tachyonic quantum fields and tachyonic 'particles' are unrelated except for an unfortunate naming convention (historically, tachyonic fields were thought to result in tachyonic particles; the name was kept around even after the mistake had been realized).
Note that tachyonic particles are not very particle-like at all, so I prefer the name 'tachyonic interaction':
Tachyons cannot be properly localized, there's a critical frame where they have no energy, their 'life-time' is space-like, both endpoints of the interaction may have the same (intrinsic) type (absorption-absorption, emission-emission), to name just some of the peculiar properties.
Recami argues (imo convincingly) that you cannot use such tachyons to violate causality.
Point 13 is also somewhat questionable, but this is more of a matter of semantics. While each of the galaxies are at rest (or in free fall, if you prefer), they are not at rest relative to one another according to parallel transport along the light ray (otherwise, there would be no red-shift). This is imo the correct way to handle relative velocities in a general-relativistic setting; the fact that their comoving distance is constant doesn't mean they are at rest in any physically meaningful way, but one can at least argue this point both ways.