  We argue that the asymmetry between diverging and converging electromagnetic
waves is just one of many asymmetries in observed phenomena that can be
explained by a past hypothesis and statistical postulate (together assigning
probabilities to different states of matter and field in the early universe).
The arrow of electromagnetic radiation is thus absorbed into a broader account
of temporal asymmetries in nature. We give an accessible introduction to the
problem of explaining the arrow of radiation and compare our preferred strategy
for explaining the arrow to three alternatives: (i) modifying the laws of
electromagnetism by adding a radiation condition requiring that electromagnetic
fields always be attributable to past sources, (ii) removing electromagnetic
fields and having particles interact directly with one another through retarded
action-at-a-distance, (iii) adopting the Wheeler-Feynman approach and having
particles interact directly through half-retarded half-advanced
action-at-a-distance. In addition to the asymmetry between diverging and
converging waves, we also consider the related asymmetry of radiation reaction.
