I dont understand how matter can be transformed to light and light can be transformed into matter? Also, how exactly does this happen when something happens to one particle and something equivalent happens to another particle of the same type on the other end of the earth instantaneously? I was trying to look up "Quantum Physics" definition of 'world' but I was unable to find anything. Can someone give me a brief explanation of the definition of 'world' in quantum physics? How do quantum physicist explain our existence?