Goldbach to and fro

The Goldbach conjecture states that "every even number greater than 2 can be written as the sum of two primes." The converse, namely "the sum of any two primes greater than 2 is an even number" is obvious. Use this applet to explore the Goldbach conjecture. [the Prime Locator allow you to slide a point on the number line. The position of the point on the number line is printed in RED when the point is on a prime number.] What questions could / would you put to your students based on this applet?