Imagine you are boarding a train. How would you describe where you
are? You might say you are sitting one meter to the left of your friend.
Perhaps you would explain that you are at the train station, which is a
half mile north of your school. You might instead say that the station
is ten blocks east of the center of town, or even 150 million kilometers
from the Sun. The descriptions are useful if they can be repeated.
INVESTIGATION