Abstract Reality

This is a fun thing to discover: That even without any tricks you can create photos that look abstract. It is just depending on your subject and the framing. If you look at this post you can find two examples with man-mode objects.
Let me now give you another two examples from natural subjects:

Rule of Thirds:


If you want to know what that is, click through the image to the flickr page and the see the comments there...

Ripples:


This is just the bark of a large tree.

So even photographs of natural subjects can look quite abstract.
Some fine examples come from photographer Bernd Uhde who produced some stunning aerial shots of the earth from baloons or planes. His book "AirRealArt - Ansichten Aufsichten" has many examples where you would have never guessed how this image was shot.