I met with a little conflict between Pauli and Einstein? Can you please help. Its a thought experiment. Consider a single crystal which is 1km long. During its formation, due to Pauli’s exclusion principle, no two electron will have same quantum state. Now consider two electron, one with E and other with E+δE. Practically they are next to each other in quantum states, so their energy varies this minimum value. But they are located, spatially, 1km apart at the extremes. One with higher energy will always try to get down but as the state is already occupied, it won’t be able to get there. My questions are – Q1. As they are at infinity to each other, i.e. can’t feel each other’s field, what physically resist this transition from E+δE to E? Q2. Suppose we provide energy to one with energy E. This would be resisted too as the higher states are also occupied. Then what happens to that one which was actually in the state before? Where will it go and what compels it to move? Q3. One with E+δE will drop down to E. Is this instantaneous? How the message of vacancy in lower state being conveyed to one that occupies it? Does the reaction time depend upon separation between the electrons? If these messages are conveyed instantaneously the relativity is at stake. Who will win Pauli or Einstein?