Relativistic Jets

[dedo]

Are you aware if the apparent superluminal velocities observed with relativistic jets from quasars is a settled issue as being caused by the angle of observation?  I have heard that this explanation is disputed, but that was some time ago.  Is it settled now?

[Halc]

There are no superluminal jets.  The effect in question was simple motion more or less towards Earth, and it only requires a velocity in our direction of > 0.5c.   So let's say a space ship begins a journey to Earth from a point 3 LY away, at a constant speed of 0.6c.  At time 0 (years), it departs, to arrive at time 5, but we don't see that departure for 3 years since it takes 3 years for light to get to us from that far away.  So at time 3 we observe the departure from 3 LY away and at time 5 it gets here.

So to us it looks like the ship took only two years to go 3 LY, superluminal, right?  No, since time for light travel was not taken into account in that calculation. Ditto for the jets, which only appear fast due to this sort of Doppler compression.