One meter.
I just want to clarify. I'm assuming the particles are not connected, or are elastic enough that stretching them by a factor of 1.005 isn't a huge deal. If you tried that with solid glass, it would probably shatter.
Come to think of it, this looks like a more complicated form of Bell's spaceship paradox.
I think you're right, but you're interpreting “sees” literally I'm not 100% sure of that, because of light aberration (the Terrell-Penrose effect).
As per a recent comment this thread is meant to voice contrarian opinions, that is anything this community tends not to agree with. Thus I ask you to post your contrarian views and upvote anything you do not agree with based on personal beliefs. Spam and trolling still needs to be downvoted.