Excellent point.<p>I think that one advantage of interstellar distance is we can effectively look back in time a great distance, so in effect we don&#x27;t have a visible radius, but a combination of time and distance.<p>We can see thousands of light years back in time, thousands of light years away. However, we don&#x27;t have that picture of Tau Ceti at 11 light years away. Perhaps thousands of years ago there was a civilization there that flourished and died - and we&#x27;ll never know because their signs of life are outside our distance&#x2F;time perception.<p>A graph of Time&#x2F;distance would be Time one axis, distance on the other and a diagonal line stretching up and to the right, showing what we could see at any given time.<p>Thoughts?<p>[edit: comment formatting ate my pretty ascii chart]