Superluminal motion. How's that possible?

[DaveC426913]

Tachyons (from Greek takhus = swift) are particles considered from a purely theoretical point of view

Actually, as previously mentioned, they're not even theoretical; they're hypothetical. There is really no reason to even suppose they might exist. It is simply that they do not violate relativity.

 

[Dickfore]

Actually, as previously mentioned, they're not even theoretical; they're hypothetical. There is really no reason to even suppose they might exist. It is simply that they do not violate relativity.

As much as I read, there are theoretical reasons to suppose their existence in some theoretical models. Thus, 'theoretical' = 'hypothetical' as long as those models are just hypotheses.

 

[vish_al210]

Well.. I was presenting a hypothetical situ.. Anyway... thanks a lot everyone...for your guidance and patience.
And yes I am clear that my assumption was wrong (about the two bodies moving at 0.9c relating to 1.8c).. and I will do the reading required to make me understand the same.
You needn't discuss the hypothetical case as (well it is hypothetical and) it has been discussed in http://en.wikipedia.org/wiki/File:Tachyon04s.gif
And I understand that the discussion on that is hypothetical and does not prove their existence as such. And my knowledge on this is very menial or non-existence... ;)
Well thanks a lot... take care...