Kirby, would I be right in thinking that you are equating the fact that the traveller's clock appears to have stopped with a time factor of infinity?

I can live with that, without being drawn back into infinite discussion. smile

One thing puzzles me, though: "Also, the traveler “sees” the observer’s clock run twice as fast (time dilation factor)…but this also means that the observer sees the traveler’s clock run half as fast as his".

I thought that both traveller and observer saw the other's clock running slow.

There never was nothing.