When tachyons became all the rage, why was the automatic assumption made that, because they seemed to travel faster than light then they must travel backwards in time? Why wasn't it just the case that perhaps here is a particle that is just faster than light, we should update our current understanding to be that nothing can travel faster than a tachyon from now on. Why is time seen as so interwoven with the speed of light (apart from the obvious fact of the way me measure time) which is, afterall, just the speed of a particular particle - why it that particle seen as so special? Please, I'm genuinely interested here, I'm not trying to be awkward as some may think. I don't have a background in physics so forgive my bumbling, I'm just questioning things from a laymans point of view. Thanks.