gahhh i've said this so many times...
it would be like speaker feedback when u put a mic near a speaker, it loops over and over until the speaker blows up or you stop it, basicly thats how a time machine would work, the air, matter etc, would end up looping until somebody stops it, 50x worse than a core meltdown, for all you know it could change one little thing in the past and the world would not exist