Re: The idea of Tachyons

Tim Little wrote:
On 2009-08-15, Wayne Throop <throopw@xxxxxxxxx> wrote:
The problem is that those "interesting effects" do indeed violate the
relativity principle. Specifically,the notion of emitting cherenkov
radiation and speeding up does

Only the very earliest theories suggested Cerenkov radiation would be
emitted. However, the assumptions were flawed.

More recent work (in the 90's IIRC) showed that isolated charged
tachyons could have fields that look superficially like Cerenkov
radiation, but conservation of charge implies that isolated charged
tachyons cannot be created any more than isolated electrons can.

Huh? That was never the suspicion of the dubiousness of charged tachyons; just as with bradyons, the Cherenkov radiation emitted by tachyons are photons, not other tachyons. Cherenkov radiation radiates away energy, not charge.

The claim is that _if_ a charged tachyon spontaneously emits Cherenkov radiation, even in a vacuum, then that would lead to violations of the relativity principle. The papers I've been finding claim this spontaneous emission doesn't happen, but I haven't found one that goes into detail (at least one that's online). I've seen other recent papers (one of which I mentioned earlier) talk freely about the Cherenkov radiation spontaneously emitted by charged tachyons, so it's not really clear to me where the consensus lies. One claimed that charged tachyons wouldn't emit Cherenkov radiation even in non-vacuum materials, which seems particularly strange.

The more serious practical problems are that no tachyons have ever
been detected with the required properties, and that (like any FTL
effects in relativity) it is difficult to reconcile local causality
with the model.

Indeed.

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