The winters were getting colder, starting earlier, lasting longer, with more snows than he could remember from childhood. As soon as man stopped adding his megatons of filth to the atmosphere each day, he thought, the atmosphere had reverted to what it must have been long ago, moister weather summer and winter, more stars than he had ever seen before, and more, it seemed, each night than the night before: the sky a clear, endless blue by day, velvet blue-black at night with blazing stars that modern man had never seen.