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During the last few weeks, I've spent quite some time thinking about Relativistic Quantum mechanics and have realized that special Relativity and Quantum mechanics can be woven together into a single theory as shown by Paul Dirac.
But then one thing that I am confused about is what happens when the wave function collapses. As far as my understanding goes, Quantum mechanics acts deterministic only until observation, the location of a particle when observed is completely random but can be described by probabilities. Special Relativity on the other hand says that the universe is like a 4D block, and everything is already there. Does this imply that the location of a particle is predetermined and it appears random because there is no way for us to send information to the past. But if, in theory we can go beyond 4 dimensions and into 5 Dimensions, can we know exactly where we'll find the particle if we observe it.
Now based on this, if in theory, we conduct the double slit experiment and we "see" the location of a particle later in time from a 5 Dimensional universe and then come back and perform the experiment, will we get the same results?
So is the universe a deterministic block or random?