ABSTRACT
Liquids and solids are condensed matter; liquids and gases are fluid matter. To make progress in appreciating the properties of materials, this chapter explores subatomic models, and move away from the image of an atom as a small hard sphere. Although faster and more efficient particle detectors have superseded them, bubble chambers provide a more intimate record of subatomic phenomena. They enable us to get a better feel for subatomic particles to facilitate our modelling of matter. Looked at superficially, the best model for an electron as a particle appears to be a very simple object. It has particular values of mass (less than a thousandth the mass of the lightest atom, hydrogen) and of electric charge, angular momentum and magnetic moment (the twisting response to an applied external magnetic field). If the charge on the interfaces can be reduced by the tunnelling of a full one-electron charge, this process can take place.
