Hello! I am a bit confused about the mechanism behind the Pauli exclusion principle. From what I read, it is motivated based on QFT arguments (for example if you don't impose antisymmetry of the fermionic wavefunction you get non-locality, or infinitely negative energies etc.) so mathematically it makes sense. However, if you try to place 2 identical fermions in the same quantum state, what exactly is the thing that exerts the force (and hence the pressure) that prevents you to do so. Mathematically if you do that, you get a zero wavefunction, so the state simply doesn't exists, but in an experiment what is actually going on? Thank you!