The question of planetary or universal destruction, from whatever cause, comes down to these questions: is the world and the universe the result of random chance or a divine creation? If it is the result of random chance several results are possible. One, the history over time principle will rule and two universes will result from the experiment, one that is destroyed and one that is not. In either event our consciousness will continue in the universe that is not destroyed and the other will seem a non-event to us. Another possibility is that a catastrophic event will occur that will not obliterate us completely. Frankly, I believe we are getting used to catastrophic events and this would just be another one. Or the experiments will not result in anything but another piece of knowledge for us to exploit, hopefully peaceably. And if the universe is a divine creation, then it is not ours to destroy. This sort of worrying occurred during the early experiments with atomic fission and fusion, and the same probabilities played out. We live in the world where we were not all destroyed by the experiments, but there were catastrophic events. As usual.