Practical uses of theoretical science

I think that art is a good thing even though it has no "practical" value. Understanding the world in which we live, itself, is a good. I think that when some high school kid reads an article in Scientific American and says "gee whiz!", that alone justifies the research.But, it's often hard to say when any research is going to have any practical value. Often theoretical reseach that is done for the sake of understanding, without any immediate practical benefits, will have benefits later. Either directly, as technology improves to the point where it can exploit the theory (for example, I doubt that Heisenberg or Shrodinger had any practicalities in mind, and certainly not the transistor, when they developed quantum mechanics), or indiriectly as the techniques and tools used in the research are exploited in other fields (I have been informed by an economics student in one of my graduate math courses that differential geometry is useful in economics - and I suspect that many of the techniques were developed during reseach in General Relativity, a field, to my knowledge, that still does not have any practical applications).Finally, as the Watson and Crick quote shows, a good scientific theory will constrain and direct one's thinking, pointing to discoveries and theories that may not immediately seem directly relevant to the topic at hand to those outside the field (or cannot accept the theories due to *ahem* religious bias).