The huge success of physics has led many to claim she is the queen of all sciences. According to this view, everything that takes place in the world could be explained, at least in principle, by the ultimate version of physics. But in truth, physics only reigns over small, easily modelled, subsections of reality. If we look at how science actually works when dealing with real-life, complex problems, we’ll see that physics plays only a small part, alongside a motley assembly of other natural and social sciences, engineering, and other disciplines, working together. The world is beautifully dappled, and requires a dappled science to explain it, argues Nancy Cartwright.

Physics, they say, is queen of the sciences. But not like Queen Victoria, who controlled only about a quarter of the world’s land area. Rather it is supposed to be as extensive as the Biblical text represents the domain of Caesar Augustus:

And there went out from Caesar Augustus a decree that all the world should be taxed.

This image requires of course a physics far from what we have ever had or can envisage having for the foreseeable future. One that is internally consistent and coherent and whose successes at treating the world do not depend on choosing among or piecing together models and theories from different sub-disciplines in physics, but one whose models flow transparently and deductively from this one, unified, consistent theory.