computer simulations

[jakepi7]

If you create a computer simulation so realistic that it takes into account every possible atomic or molecular position and composition- will that sim be the same as the real thing? Leaving out a priori considerations or how powerful the computer would have to be to do such a thing would man finally be able to create anything in this universe? Is this universe a sim of a possible universe? If so imagine who is at the controls and who is writing the program.If you use every atom in the universe to comprise the computer then perhaps you can make a sim as described.