Page:In the high heavens.djvu/251

 hundredth, probably not the thousandth, perhaps not the millionth part of the total quantity of matter.

On the question as to whether space is finite, our observations with the telescope have but little information to give. The question here involved is rather of a metaphysical complexion. The extent of space depends more upon the facts of consciousness than upon those of astronomical observation. It may, perhaps, simplify the discussion of the subject if we first of all consider the question as to whether the quantity of matter in the universe may be presumed to be infinite or not. We can put the question into a perfectly concise form by reflecting that every particle of matter, whether solid, liquid, or gaseous, is composed of molecules. No doubt these molecules are so numerous that even in the air we breathe the capacity of a lady's thimble would contain a multitude of molecules so great that it has to be enumerated by billions. But we are not at present merely concerned with the actual number of molecules that may exist in the atmosphere, even in its whole extent, or in the whole earth, or in the whole sun. Let us try to conceive the number of molecules that are present in all the stars, bright and dark, which exist not only within those regions of space accessible to our telescopes, but elsewhere as well. In short, let us try to conjure up in our imagination the kind of figures which are to express the total number of molecules in the universe. Is that number finite, or is it not?

This is, perhaps, one of the most fundamental questions in nature which could possibly be proposed. Let us consider the consequences which would follow from adopting a negative answer to this question. If we suppose that the number of molecules is indeed infinite, then we are