This is sad. I am not able to access YouTube on the third consecutive day. I so much want to listen to your videos, GW! 
http://www.jimloy.com/physics/quantum.htm
http://wiki.answers.com/Q/What_is_a_quantum_leap

http://www.jimloy.com/physics/quantum.htm
http://wiki.answers.com/Q/What_is_a_quantum_leap