Hi everyone. I had a question to ask about quantum teleportation and quantum entanglement. I read that recently, some scientists managed to make an altercation to one quantum particle (a photon, i think) and the same change occured to the other particle that was 143 km away. but there were parts that I couldn't understand. Firstly, I could not find anything on the web about "how" they managed to make an altercation to the photon. In one video I saw, it said that the spin was changed, still without mentioning how. Secondly, because actually measuring the particle would remove its entanglement and the superposition state, the scientists had another photon in a different quantum state and then measured the quantum state of the first photo relative to the second photon. What does this mean?