29th August 2018
Time travel is impossible
A question is still asked: can we go back in time? The surprising thing is that some physicists are still tinkering with this question even when the answer is staring right in their face.
The key principle that applies to this question is not the equations and principle of space-time but the principle of conservation of energy. The total amount of energy in the universe is constant. Therefore, regardless of its quantum mechanical properties, the sum of the energy of all particles (visible or dark) and waves cannot change.
Energy has a powerful property: it is only found in its current state, with all previous and future states being bereft of energy and hence reality.
The concept of space-time block is mathematically correct but all states of space-time except the current state are physically non-existent.
Hence you can’t get real people (i.e. energy) into the past (or future).
Btw, I believe (this is only an unproven belief) that we have an infinity of universes somewhat similar to ours but with different characteristics. The energy within each of these infinity of universes is constant within that universe. Each of these universes exists in a “current” state in which its entire energy actually exists in particular forms. All previous states are not real after that moment has passed.