Sure Biden hasn't done anything to try to prevent the heat death of the universe, and Biden has never mentioned the heat death of the universe, but Trump DEFINITELY won't do anything to try to prevent the heat death of the universe. Biden might though, there's a possibility no matter how small. So if you care about the universe and everything in it then you HAVE to vote for Biden, and then once he's in office, THEN you can start trying to push him towards preventing the heat death of the universe. That's literally the only possible way we even have the slightest chance of preventing the total and complete destruction of the entire universe.