Bryan Roberts (London School of Economics)
I argue that there are circumstances in which an antiparticle really is 'physically equivalent' to a particle moving backwards in time. I begin with an account of what the latter means, which I call the 'Many Arrows' account of temporal direction. After discussing some shortcomings of the Earman and Arntzenius-Greaves perspectives, I give an account of the meaning of 'charge', which produces a unique derivation of the charge conjugation operator. I then state a precise form of the Wheeler-Feynman thesis and verify this thesis in simple examples and indicate how it extends to a certain class of CPT-invariant field theories.
