 How do humans perceive the transportation devices?
But then, how could a group of loosely spaced grains of sand possibly have a nervous system? These creatures were not only humanoid, but definitely human, although more slight of build than earth people. But up to now the tube and the chain was the only evidence of an advanced technology, unless the ancient inscriptions in the stone wall of the pool, and the statues lining the wall were evidences. It is impossible to move a physical body from one place to another by a mere thought and a tiny instrument, yet you have done so. You travel by a means even I cannot fully understand, yet you speak of time as if some event were about to take place. It has to do with what comes after physical existence, not with existence itself.
 They are luxury goods that many have strong independent motivation to acquire
 They are only used to transport between worlds but humans wish they could be used for local travel  They are untrustworthy technology that are dangerous to implant  They are luxury goods that many have strong independent motivation to acquire  They are commodities in the current economy