They say that photography is the art of capturing the light. But, light is pretty slippery stuff. Rather than capturing the light, I believe that photographers actually borrow from it, enhance it, and pay it back every time someone looks at his or her pictures. The real joy of photography is seeing the light, appreciating it, and then sharing it with others.
Choosing the subject of your photographs is a very personal measure of your own aesthetics. Your own vision of beauty will determine your subject matter, whether it is portraiture and putting a human face to our journeys, or landscapes and portraying the nature of our biology.
I choose to tell the story of great architecture and feats of engineering. As a scientist, I have always wondered how things are put together and how they work. And the photos I produce help me explain it all to myself.