nary when it started on its journey, and
would not be in the least affected by anything that happened there
after it left; so that we really see the sun not as he _is_, but as he
was eight minutes ago. That is to say that if anything important took
place in the sun--the formation of a new sun-spot, for instance--an
astronomer who was watching the orb through his telescope at the time
would be quite unaware of the incident while it was happening, since
the ray of light bearing the news would not reach him until more than
eight minutes later.

The difference is more striking when we consider the fixed stars,
because in their case the distances are so enormously greater. The
pole star, for example, is so far off that light, travelling at the
inconceivable speed above mentioned, takes a little more than fifty
years to reach our eyes; and from that follows the strange but
inevitable inference that we see the pole star not as and where it is
at this moment, but as and where it was fifty years ago. Nay, if
to-morrow some cosmic catastrophe were to shatter the pole star into
fragments, we should still see it peacefully shining in the sky all
the rest of our lives; our children would grow up to middle age and
gather their children about them in turn before the news of that
tremendous accident reached any terrestrial eye. In the same way there
are other stars so far distant that light takes thousands of years to
travel from them to us, and with reference to their condition our
information is therefore thousands of years behind time.

Now carry the argument a step farther. Suppose that we were able to
place a man at the distance of 186,000 miles from the earth, and yet
to endow him with the wonderful faculty of being able from that
distance to see what was happening here as clearly as though he were
still close beside us. It is evident that a man so placed would see
everything a second after the time when it really happened, and so at
the present moment he would be seeing what happened a second ago.
Double the distance, and he would be two seconds behind time, and so
on; remove him to the distance of the sun (still allowing him to
preserve the same mysterious power of sight) and he would look down
and watch you doing not what you _are_ doing now, but what you _were_
doing eight minutes and a quarter ago. Carry him away to the pole
star, and he would see passing before his eyes the events of fifty
years ago; he would be watching