The Past and Future of the Mississippi

In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the old Oolitic Silurian Period, must a million years ago next November, the Lower Mississippi River was upward of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-rod. And by the ...

 What is a "Law of Nature"?

Our modern understanding of the term "law of nature" is an issue philosophers argue at length, and it is a more subde question than one may at first think. For example, the philosopher John W. Carroll compared the statement "All gold spheres are less than a mile in diameter" to a statement like "All uranium-23 spheres are less than a mile in diameter." Our observations of the world tell us that there are no gold spheres larger than a mile wide, and we can be pretty confident there never will ...