It's difficult to find a clear definition of abstract photography. Many agree that photos falling into that category convey a non-literal representation of the subject matter, expressing forms, colors, shapes or shadows that represent something. I like to think of abstract photography as anything that could be interpreted in multiple ways. That may sound too broad, but consider the ice structure below, taken on the banks of the Cedar River near Palisades State Park in Eastern Iowa.
The thin layers of ice were formed by gentle waves from the river and froze in interesting patterns over time. At first glance, this photo could be interpreted as a painting, a rock formation, or any number of things. But as you key into the patterns and color, it becomes clear it's ice. Some viewers will see shapes or objects embedded in the patterns, while others will see nothing but the photo itself.
So is this an abstract photo? Yes and no. Taken from a single shot, it's an exact duplicate of what really existed, but the way it's cropped may lead the viewer to other avenues since there's no context.
What I like about these photos is the different way people are wired visually, thus the interpretive aspect of viewing comes into play. To me, the photo has a little bit of science fiction in it...in the upper right where the ice looks more marbled and crystallized, it reminds me of a head with some kind of clear space helmet on, with the the body laying across the frame with the left arm along the bottom. Am I crazy? Perhaps, but I'll bet others see something different.
An argument could be made that every photo has the potential for multiple interpretations, and indeed, most good photos have that characteristic, so one could argue that everything is abstract. But in the end, most would probably agree that there's a line somewhere in our brain that screams "abstract" vs. "awesome landscape" or "beautiful flower".
The other cool thing about abstracts is that there are a bunch of different kinds...impressionistic, literal images out of context, extreme colors, shapes or forms, and just about anything else that has a pattern or shape to it. Nature has produced the most amazing shapes and patterns we've ever seen, and if you add the cosmos in the mix, abstracts are quite breathtaking and essentially everywhere.
The next time you see an interesting pattern, shape or set of colors, explore it and try to capture the essence of the scene. You may find that capturing our world in a different way can be inspiring and fun!