I just started reading Stern Gerlach Experiment and this thought crossed my mind. Totally a hypothetical question. If I pass an electron and positron through separate SG apparatuses, I will know in which spin state each particle has collapsed. But afterwords I let electron-positron pair annihilate to produce 2 photons. I let these photon Interact with each other and again produce an electron-positron pair. So, if I again check the spin state of these particles separately, in the same direction as before, will I get the same result or is it again completely random? P.S. I am just a school student trying to learn something difficult for me to understand. So please spare my ignorance.