Star Wars: 10 Greatest Disturbances In The Force
4. The Emperor Fears Luke's Potential
"The son of Skywalker must not become a Jedi." As Luke's journey takes him from being an annoying farm boy to becoming the most powerful rebel pilot in the galaxy, the emperor senses something must be done. The disturbance caused by Luke's development informs the emperor of Anakin Skywalker's offspring; and as Luke's power grows, so does the disturbance, which causes the emperor great concern.
It was dangerous and possibly stupid for Palpatine to send his Sith apprentice after his own son, but it could be argued his arrogance was his greatest weakness. Perhaps Palpatine figured as Yoda and Obi-Wan did, that the dark side dominates destiny forever. Yet it could also be said the emperor saw one Skywalker killing another as a win-win situation he could exploit based on the rule of two.
The disturbance caused by Luke's developing powers ranks high on this list because it informs Vader of his son's existence and sets in motion the events leading up to their first confrontation in Cloud City.