Is Simultaneity an Illusion? It is if one agrees with Einstein’s theory of special relativity. It is not if one agrees with Alfred North Whitehead’s contention that we do immediately apprehend the simultaneity of spatially separated events. Whitehead’s assertion is based on a desire by most physicists, who need simultaneity of events, which is the same for all human beings at rest relative to each other on the same coordinate system or frame of reference. In this universe of ours, we can rightfully make the assertion that simultaneous events does not exist. But we can also make the assertion that simultaneity exists at the singularity of the big bang, which space-time structure is zero. This is the one and only event that can be simultaneous for two parallel universes, two mirrored worlds. Since simultaneity only happens once for two mirror-worlds, this implies that the flow of time is bi-directional. One world is growing younger and the other is growing older. In these two worlds, they have their own Einstein. One Einstein for one world and one anti-Einstein for the other anti-world. The Einstein in one of these two worlds formulated general relativity and made the blunder in assertion that the universe is static until Hubble came along and proved him wrong. But by this time the anti-Einstein in the other have been dead for zillions and zillions of years and his general relativity was correct up to the maximum expansion phase of that universe since it is now undergoing a contracting phase. These analogies show the independent character of physical laws, which can only be true for half of the phases of the mirror worlds and not sacrificing their symmetries. Simultaneity happens only at time equals zero.