Archimedes and Ευρηκα

In his Learn to Read New Testament Greek David Alan Black tells the story of the Greek philosopher Archimedes and his discovery of the law of buoyancy while taking a bath. Dr. Black says, "...he is reported to have scampered (without his clothes) through the streets of Athens shouting, ευρηκα, ευρηκα, 'I have found it, I have found it!' What Archimedes apparently meant by the use of ευρηκα (the perfect of ευρισκω) was that his discovery had become part of his intellectual awareness. If, on the other hand, he had found a drachma on the street and then lost it before he got home, he probably would've used the aorist ευρον, "I found it," which says nothing about the existing state of affairs."