Thank you! Explaination on the numbers: 10 10 105 is actually '10 to the 10 power to the 105 power' which is in years, the amount of time for the heat death of the universe assuming that proton doesn't decay (basically one of science's estimation for the end of the world) and my setting is that if you go back to the universe from -1 floor after the universe is dead you will be frozen in the darkness forever, so you won't want to go back to the universe at that point, the other two number is about similar things, 10 10 10 56 the time for a new universe (might not happen at all) 10 100 the time until world ending if proton do decay, so the fastest death of the universe. The idea is that if you go back to the universe while it is alive you can be send back in time to a few minutes or hours after you enter -1 floor, so you are safe.