What do physicists study? It seems a simple enough question, but if you talk to a modern physicist who isn't in 'speak slowly for ordinary folk' mode, you might suspect it's not the world as we know it. I'd say about nine times out of ten when I ask a friendly physicist to elucidate some aspect of modern physics, what they say provides no light on reality. And this thought has been around a long time. In effect the idea that we aren't talking about reality is the picture Plato had, often summed up in the image of the cave - that we are in a cave and can only study the shadows of reality on the wall of the cave, not the 'true' world that is not part of our world. Plato took this viewpoint from an arbitrary philosophical basis that the 'real' world was perfect - so, for instance the real world might contain the perfect archetype of 'dog' where in our cave we just experience a shadow of dogness. Something closer to modern science comes...