In the above picture it is clear that the transition from normal to superconducting states is not infinitesimally sharp, it drops from around 4.22K ~ end at 4.20K. I have two questions for this: 1) I wondering, what can be seen if taking a snap shot in the middle, say @ 4.21K? Would I see cooper pairs and free electrons mixed? 2) But as I know, cooper pairs would not "mix" with free electrons, because the exist of free electrons will disturb or say, break the condensed states of cooper pairs, it means either 100% cooper pairs or 100% free electrons in the conductor. Is my understanding right? THANKS A LOT FOR HELPING!!