Sirius had indeed moved with respect to the position of nearby stars. Stars like our sun are not fixed in their position in the spiral arms of the Milky Way. Eons ago, the sun was not in its current arm, and eons from now it will wander out of it to other parts of our galaxy. The real motion of stars doesn't seem so important to us today. But there was a time in our history when the news was devastating.
Life is full of unpredictability.
We fear death and change. The fixed position of the stars were looked upon as a sign of god's perfection. Anyone suggesting otherwise committed an affront to God. Times have changed and with them our understanding. We have come to realize that we are caught up in a series of swirls within swirls within swirls.