Why would anybody want to go back in time to do this?
Why not change the narrative so that the Big Bang is actually very small, and the entire universe exist only for a smatter of a second in a collision chamber in some advanced alien society's version of the LHC? They (the aliens) collide a few particles at close to the speed of light (
c at
their scale), and are awe-struck at the few nanoseconds the debris fly away from the collision, not realising that in that debris field, consciousness arose in the form of humans on a much, much smaller scale - tiny sub-atomic particles on the alien scale being entire galaxies on the human scale?
The fiery plasma from the collision contains billions of year's evolution, it contains the rise and fall of the Roman empire, the first and second World Wars, everything from the Big Bang to the final icy death of the universe. And black holes are the particles that formed from sub-atomic particles, and at the end of the experiment, there are only particles left, as expected.
Somehow, the alien scientists detect the presence of intelligence in this collision debris, where (at our scale) it will be millions, if not billions of years in the future where we get to harnass the energy of entire galaxies and are able to let our presence be known to the alien's scale.
And then, at the end, the scientist aliens who conduct the experiment look up to the stars in
their sky, and realise that they, too, are merely the result of some particle-collider existing at an even bigger scale...
